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Full text of "Grouting in soils"

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leport No. FHWA-RD-76 

IROUTING IN SOILS 



-26 



Dept. of Transportation 



NUVOS 1976 



Library 



Vol.1. A STATE-OF-THE-ART REPORT 



Joe Herndon, Tom Lenahan 




S? "4TES o* 



June 1976 
Final Report 



THIS DOCUMENT IS AVAILABLE TO THE PUBLIC 
THROUGH THE NATIONAL TECHNICAL INFORMATION 
SERVICE, SPRINGFIELD, VIRGINIA 22161 

Prepared for 

FEDERAL HIGHWAY ADMINISTRATION 
Offices of Research & Development 
Washington. D.C. 20590 



NOTICE 



This document is disseminated under the sponsorship of the 
Department of Transportation in the interest of information 
exchange. The United States Government assumes no liability 
for its contents or their use. 

The contents of this report reflect the views of Halliburton 
Services - Duncan, Oklahoma, which is responsible for the 
facts and the accuracy of the data presented herein. The 
contents do not necessarily reflect the official views or 
policy of the Department of Transportation. This report 
does not constitute a standard, specification, or regulation. 

The United States Government does not endorse products or 
manufacturers. Trade or manufacturers' names appear herein 
only because they are considered essential to the object of 
this document. 



FHWA DISTRIBUTION 

Sufficient copies of this report are being distributed by 
FHWA Bulletin to provide two copies to each regional office, 
one copy to each division office, and two copies to each State 
highway department. Direct distribution is being made to the 
division offices. 



ye 
.4$ 



Technical Report Documentation Page 



s "7^- . 



1 . Report No. 

FHWA-RD-76-26 



2. G 



overnment Accessi 



ion N 



3. Recipient's Catalog No. 



4. Title and Subtitle 

GROUTING IN SOILS 

VOL. 1 -A STATE-OF-THE-ART REPORT 



5. Report Date 



June 1976 



6. Performing Organization Code 



8. Performing Organization Report No. 



7. Author's) 



Joe Herndon, Tom Lenahan 



9. Perfpr, 



Perfprmjng Organization Na^ne and Addres 

Halliburton Services 
P. 0. Drawer 1431 
Duncan, OK. 73533 



10. Work.Um.t No. (TRAIS) 



2 



11. Controct or Grant No. 

DOT-FH-11-8517 



12. Sponsoring Agency Name and Address 

Offices of Research and Development 
Federal Highway Administration 
U.S. Department of Transportation 
Washington, D.C. 20590 



13. Type of Report and Period Covered 

Final Report 



14. Sponsoring Agency Code 



„__ 



15. Supplementary Notes 

FHWA Contract Manager: J. R. Sail berg (HRS-11) 



16. Abstract 

This report summarizes present grouting technology applicable to soils. 
It includes all aspects of grouting, from theory to present practices; from 
the history of grouting to recommendations for improved techniques. The 
, information was obtained from published and unpublished reports, job in- 
spections, interviews of grouting specialists in both the United States and 
Europe, and the writers' past experience. 

A companion report, Volume 2 (FHWA-RD-76-27) is entitled "Design and 
Operations Manual ." 



Dept. of Transportation 




NUV 3 1976 






Library 





17. Key Words 

Foundation construction, soil grouting 
water control, grouts, grout tech- 
niques injection, contracts. 



18. Distribution Stotement 



No restrictions. This document is avail 
able through the National Technical 
Information Service, Springfield, 
Virginia 22161. 



19. Security Classif. (of this report) 

Unclassified 



20. Security Classif. (of this page) 

Unclassified 



21. No. of Pages 

303 



22. Price 



Form DOT F 1700.7 (8-72) 



Reproduction of completed page authorized 



PREFACE 



Volume 1 of this two-volume report presents the current state-of- 
the-art on all aspects of grouting from theory to field practices. 
Particular applications are given for cut-and-cover construction and 
soft ground tunneling. Conclusions are drawn, and recommendations are 
made for improvements in the grouting field. Also included in this 
volume are: 

(1) A summary of the patents applicable to grouting. 

(2) A list of grouting specialists, and material and 
equipment suppliers. 

(3) A bibliography of publications on grouting. 

(4) Unpublished case histories of grouting jobs. 

This report is based on information from four sources: interviews 
with companies in the grouting or construction business, inspections 
of grouting jobs, reviews of the literature, and personal experiences 
of the writers. Information for the report was difficult to obtain 
because of the scarcity of case histories on soil grouting. Contract 
documents do not normally require a written report, so wery few 
detailed records have been kept on grouting jobs by either construction 
companies or engineering firms. Documentation on successful jobs is 
generally limited to that used by the grouting companies in their 
advertising brochures, papers published by grouting personnel and a few 
unpublished reports. On European jobs, pressure and flow rate charts 
are made during the grout injection and given to the owner to document 
the grouting work; however, reports are not usually written about the 
grouting job. 



n 



ACKNOWLEDGEMENTS 



The authors acknowledge with gratitude the assistance given by 
the following in the preparation of this report: 

To Dr. R. L. Handy of Iowa State University for his contribu- 
tions to the sections dealing with grouting theory and his review 
and helpful comments on the entire report. 

To Mr. J. R. Sail berg, Contract Manager for the Federal Highway 
Administration, Department of Transportation, for his helpful sugges- 
tions and constructive criticism throughout the entire study. 

To Mr. Carl Bock, Bechtel Associates, Washington, D. C, for 
his review of the reports and his pertinent comments and suggestions, 

To Mrs. Clara Bishop of Halliburton Services for her assistance 
in the accumulation of literature and her patience and endurance in 
typing of the report. 

And, to all the following people who cooperated in the study by 
giving time for interviews or furnishing materials for the report. 

American Cyanamid Company - Wayne, New Jersey 
William J. Clarke 

Antwerpse Bouwwerken Verbeeck, Antwerp, Belgium 
Luc Adriaenssen 

Bechtel Associates - Washington, D. C. 
Frank C. Waram 
Jim Daley 
Jim McDermott 

The Cementation Company, Ltd. - Croydon, Surrey, England 
Peter Jessop 
John Hi si am 
Dr. R. A. Scott 

Cementation Research, Ltd. - Rickmansworth, Herts, England 
F. H. Hughes 
Tom Hutchinson 
Mike Ling 

Dames and Moore - Chicago, Illinois 
Dr. Pete Conroy 
Dr. Charles Heidengren 

ECI - Soletanche, Inc. - Pittsburgh, Pennsylvania 
David J. D'Appolonia 

iii 



E.N.E.L. (Italian National Electric) - Rome, Italy 
Dr. Capozza 

Foundation Sciences, Inc. - Portland, Oregon 
Donald J. Dodds 

Fruin-Collon Corporation - Washington, D. C. 
Ron Bills 
George Williamson 

Geosonda - Rome, Italy 
CI audio Soccodato 
Lucio Diamanti 

Geotecna - Milan, Italy 
Dr. Nicola Allaria 
Dr. Meisina 

Geron Restoration Corporation - Saratoga Springs, New York 
Norman Wagner 

Grow Tunnel ers - New York, New York 
Paul DeMarco 
Henry Jacoby 
George Fox 

Harza Engineering Company - Chicago, Illinois 
Keith Willey 
Dr. Ray LaRusso 
Svanti Hjertberg 

Hayward Baker Grouting Company - Odenton, Maryland 
Wallace H. Baker 

Horn Construction Company, Merrick, L.I., New York 
Burton Kassap 
Steve Pirrelli 

Hunt Process Company - Santa Fe Springs, California 
Slade Rathbun 

I.C.O.S. - Milan, Italy 
Dr. Nicolai Jurina 
Mr. Bellini 

Intrusion Prepakt Company - Cleveland, Ohio 
Paul Smith 
Bruce Lamberton 

Iowa State University - Ames, Iowa 
Dr. R. L. Handy 

iv 



METRO - Amsterdam, Netherlands 

METRO - Hamburg, Germany 
Rudolph Stoppenbrink 

METRO - Hanover, Germany 
Frederick Weiss 

Metropolitana Milanese s.p.s. - Milan, Italy 
Antonio Salvini 

Nederhorst Grondtechniek - Gouda, Netherlands 
K. F. Brons 

Parsons, Brinkerhoff, Quade & Douglas 

Peter VanderSloot - St. Louis, Missouri 

Tom Kuesel - New York, New York 

Dr. Birger Schmidt - New York, New York 

Penetryn System, Inc. - Latham, New York 
Ed Stringham 
A. B. Colthorp 

PRE-METRO M.I.V.A., Antwerpen, Belgium 
L. DeRoy 

Pressure Grout Company - Daly City, California 
Ed Graf 

Raymond International, Inc. - Cherry Hill, New Jersey 
Joe P. Welsh 

S.A.R.A. (Societa Autostrada Romane e Abruzzisi), L'Aquilla, Italy 
Dr. Castellano 
Sr. Marini 

Soil Mechanics, Ltd. - Bracknell, Berkshire, England 
Kristin Moller 
Dr. B. 0. Skipp 

Soletanche Entreprise - Lyon, France 
Philippe Mahler 
Jean Pierre Banachau 

Soletanche Entreprise - Paris, France 
Guy LeSciellour 
Jacque Levallois 

Soletanche Laboratory - Montereau, France 
Dr. C. Caron 



SWIBO - Vienna, Austria 
Jacques Gardes 
Bernard Tarralle 

TAMS Consulting Engineers - New York, New York 

Terra-Chem, Inc. - Dayton, New Jersey 
Herbert L. Parsons 

Terrafreeze Corporation - Lorton, Virginia 
Bernd Braun 

U-Bahn - Vienna, Austria 

Dipl . Ing. Walter Hinkel 

Warner Engineering Services - Los Angeles, California 
James Warner 



VI 



TABLE OF CONTENTS 

Documentation Page ------------------------- i 

Preface- ------------------------------ ii 

Acknowledgements -------------------------- i i i 

Table of Contents- vii 

List of Figures --------_--____._________ X1 - 

List of Tables xiii 

List of Symbols- -------------------------- xiv 

1. INTRODUCTION 1 

2. GROUTING PRACTICES 3 

A. Grouting Fundamentals- ---------- 

B. Grouting Theory (For True Solution Grouts) -------- 3 

1. Physical Characteristics of Fluids -------- - 5 

2. Fluid Pressure Under Static Conditions ------- 5 

a. Variations of Pressure with 

Depth in a Liquid -------------- 5 

3. Pressure Measurement ---------------- 6 

a. Pressure Measurement Devices --------- 7 

4. Flow of Water Under Pressure ------------ 7 

a. Fluid in Motion- --------------- 7 

b. Rate of Flow 8 

c. Energy Equation- --------------- 9 

d. Friction Loss in Pipes and Fittings- ----- 11 

5. Flow Through Soils ----------------- 12 

a. Flow of Water- ---------------- 12 

b. Flow of Viscous Grouts ------------ 12 

C. History of Grouting- ------------------- 14 

D. Current Practices- -------------------- 19 

E. Evaluation of Current Grouting Practices --------- 26 

3. GROUTING APPLICATIONS 28 

A. Waterstop 28 

1. Dam Foundations- ------------------ 28 

2. Cut-and-Cover 29 

3. Tunnel Boring- ------------------- 33 

4. Remedial Grouting- ----------------- 34 

5. Slurry Trench- ------------------- 34 

vii 



B. Strengthen Natural Soil Deposits- ------------ 34 

1. Under Footings and Foundations- ---------- 34 

2. For Tunnel Excavation --------------- 36 

3. In Cut-and-Cover- ----------------- 40 

C. Compaction Grouting ------------------- 41 

D. Tieback Anchorages- ------------------- 41 

E. Backpacking Tunnel Liners ---------------- 45 

F. Alternate Use of Freezing ---------------- 45 

4. SITE INVESTIGATION AND SOIL TESTING 48 

A. Drilling and Sampling- ------------------ 49 

B. Soil Properties Affecting Grouting ------------ 49 

1. Permeability -------------------- 50 

a. Permeameter Tests for Permeability ------ 50 

b. In Situ Tests for Permeability -------- 52 

2. Porosity ---------------------- 55 

3. Particle Size Distribution ------------- 56 

4. Pore Size Distribution --------------- 59 

a. Mercury Injection Method ----------- 60 

b. Errors in Assumptions- ------------ 62 

c. Analysis of Groutability Related to Soil Pore 

Size and Grout Particle Size- -------- 63 

d. Grouting Pressure and Seepage Forces ----- 64 

C. Geographical and Geological Data ------------- 64 

5. GROUT MATERIAL SELECTION 66 

A. General Considerations ------------------ 66 

B. Choice of Applicable Grout Groups- ------------ 66 

C. Grout Properties --------------------- 72 

1. Viscosity Characteristics- ------------- 72 

2. Setting Time -------------------- 76 

3. Strength ---------------------- 77 

a. Strength Theory- --------------- 80 

b. Strength Tests of Grout Material ------- 83 

4. Water Tightness- ------------------ 84 

5. Stability or Permanence- -------------- 84 

6. Toxicity ---------------------- 85 

D. Grout Testing - Laboratory and Field ----------- 85 

6. GROUT EQUIPMENT 86 

A. Drilling and Driving Equipment -------------- 86 

B. Mixing and Pumping Equipment --------------- 86 

1. Handling of Materials- --------------- 86 

2. Grout Mixing and Pumping -------------- 88 

a. Cement Type Grout- -------------- 88 

b. Chemical Grouts 88 

C. Injection Piping--------------------- 91 

1. Drive Points 93 

2. Pipe in Boreholes- ----------------- 94 

vi i i 



3. Tube a Manchette and Stabilator ------------ 95 

4. Other Types of Injection Pipes- ------------ 95 

D. Monitoring Equipment- ------------------ 98 

7. GROUT INJECTION PRINCIPLES 99 

A. Theoretical Considerations- --------------- 99 

1. Mathematical Theory ---------------- 99 

a. Water Saturated Soils------------ 99 

b. Injection from Slotted Pipe or 

Tube a Manchette --------------106 

c. Effect of Dry Soils 107 

d. Non-Newtonian Grouts and the Limiting Sphere- 108 

2. Theory of In Situ Stress Modification by Grouting - 113 

a. Grouting Pressure to Induce Shear Failure - - 117 

b. Grouting Pressure Against Walls ------- 119 

c. Grouting Pressure in Tunneling- ------- 122 

d. Landslides 123 

e. Foundation Grouting -------------123 

B. Practical Aspects --- 123 

1. Grout Penetration -----------------123 

2. Grid Patterns - 125 

3. Job Planning 128 

C. Injection Quality Control ----------------130 

D. Safety and Environmental Considerations --------- 130 

8. FIELD TESTS OF GROUTED SOILS - 132 

A. Introduction- ---------------------- 132 

B. Current Practices -------------------- 132 

1. Sampling and Laboratory Testing ---------- 132 

2. Permeability Testing- ---------------134 

3. In Situ Strength Tests- -------------- 134 

a. Pressuremeter ---------------- 134 

b. Borehole Shear Test ------------- 137 

c. Goodman Jack- ---------------- 139 

4. Relation of Test Information to Unconfined 

Compressive Strength ---------------140 

5. Performance Evaluation- --------------141 

C. New Concepts 141 

9. SLURRY TRENCH AND DIAPHRAGM WALL CONSTRUCTION - 143 

A. Current Practices --------------------143 

1. Steel Beam and Concrete Panel Wall- -------- 145 

2. Jointed-End Panels 146 

3. Precast Concrete Panels --------------146 

4. Other Excavation Methods- -------------147 

B. Engineering Characteristics of Trench Slurry- ------ 148 

C. Specification and Cost Data ---------------152 



IX 



10. CONTRACT DOCUMENTS AND SPECIFICATIONS 154 

A. Current United States Contracting Practices ------ 154 

B. Current European Contracting Practices- -------- 155 

C. Contractural Problems with Grouting Contractors - - - - 156 

11. SUMMARY AND EVALUATION- - 158 

12. CONCLUSIONS 163 

13. RECOMMENDATIONS 167 

14. REFERENCES 169 

15. APPENDIX 175 

A. Glossary of Terms ------------------- 176 

B. Bibliography 180 

C. Case Histories - 201 

D. Testing Information ------------------ 241 

1. In Situ Permeability Test Procedure ------- 241 

2. Laboratory Grout Distribution Tests ------- 245 

E. Sample Specifications ----------------- 250 

F. Applicable Patents 259 

G. Grouting Specialists- ----------------- 277 

H. Chemical Grouting Material Suppliers- --------- 282 

I. Grouting Equipment Suppliers- ------------- 283 

J. Ben torn" te Suppliers ------------------ 284 

K. Current Research in Grouting Technology -------- 285 



LIST OF FIGURES 

Figure Page 

1 Typical Grouting Job ------------------- 4 

2 Pressure in a Fluid- ------------------- 6 

3 Velocity Profile --------------------- 8 

4 Energy Gradient --------------------- 10 

5 Temperature Effects on Viscosity of Water- -------- 13 

6 Diagram of Joosten Grouting Process- ----------- 16 

7 Schematic of Job Layout- ----------------- 18 

8 Slurry Trench, Diaphragm Wall and Grouting on French Job - 20 

9 Dual Piston Type Grouting Pumps and Mixing Tanks ----- 20 

10 Small Grouting Job in Cut-and-Cover Construction ----- 23 

11 Grouting to Consolidate Sand Behind Wood Lagging ----- 23 

12 Large Grouting Job Site and Equipment- ---------- 24 

13 Van Mounted Grout Pumps- ----------------- 24 

14 Packer Element and Connector Tubing Used In Europe - - - - 25 

15 Machine for Placing Packer Element and Connector Tubing- - 25 

16 Grouting Tubes in Place for Grout Injection- ------- 26 

17 New Style French Grout Curtain -------------- 29 

18 Cut-and-Cover Grouting for Metro System in France- - - - - 30 

19 Strength Curve of Special Grout Used with Prefabricated 

Wall Installation -------------------- 31 

20 Prefabricated Concrete Diaphragm Wall Construction - - - - 32 

21 Grout Curtain Protecting Bridge Piers- ---------- 33 

22 Grouting Under Footing of British Hospital -------- 35 

23 Hamburg (Germany) Subway Grouting- ------------ 37 

24 Munich Germany Expressway Grouting ------------ 38 

25 Grouting from Galleries in Paris Metro System- ------ 39 

26 Running Ground Encountered in Tunneling- --------- 40 

27 Schematic of Compaction Grouting to Level Tank ------ 42 

28 Open Cut Construction with Both Strut Bracing and 

Tieback Anchorages- ------------------- 43 

29 Placing Tieback Anchor in Sheet Steel Wall ' 44 

30 Typical Detail of Earth Tieback Anchor ---------- 44 

31 Alternative Refrigeration Approaches ----------- 46 

32 Falling Head Permeameter ----------------- 51 

33 Particle Size Distribution Curve ------------- 58 

34 Correlation of Effective Diameter and Permeability - - - - 59 

35 Pore-Size Distribution Curves for Loess Soil ------ - 61 

36 Sheet Piling on Obstruction Missed in Site Investigation - 64 

37 Soil Limits for Grout Injectability- ----------- 71 

38 Soil and Grout Materials Grain-Size Curves -------- 73 

39 Limits of Groutability of Sands by Particulate Grouts- - - 74 

40 Viscosities of Various Grouts- -------------- 75 

41 Cement Consistometer ------------------- 76 

42 Compressive Strength of Various Grouts ---------- 76 

43 Soil Strength Characteristics ____-___-- 81 

44 Drilling Machine on Grout Job in France- --------- 87 

xi 



Figure Page 

45 Batch Plant for Large Grouting Operation- --------- 87 

46 Progressive Cavity Type Grouting Pump ----------- 89 

47 Cutaway View of Progressive Cavity Pump ---------- 89 

48 Dual Pump Grouting Unit 90 

49 Trailer Mounted Grout Pumps ---------------- gi 

50 Electronic Console for Grout Pump Automation- ------- 92 

51 Grout Pumps and Mixing Tanks in Van Unit- -------- - 92 

52 Recording Gauges and Pump Controls in Grouting Trailer- - - 93 

53 Pump Open Drive Point for Grout Injection --------- 94 

54 Tube a Manchette- ------------- 96 

55 Operational Principle of Tube a Manchette --------- 96 

56 Stabilator Valve Tube -- 97 

57 Schematic of Grout Principle- --------------- 100 

58 Newtonian vs. Plastic Flow- ----------------109 

59 Force Affecting Flow of a Fluid Element in a Cylindrical 

Tube of Diameter D- ---------------- ---"110 

60 Comparison of Shearing Stress and Velocity of Newtonian 

and Bingham Plastic Flow- ---------------- m 

61 Pore Pressure Effect on Stress -------------- 114 

62 Relation Between Principal Shearing and Normal Stress- - - 115 

63 Effect of Grouting Pore Pressure on Effective Stresses - - 116 

64 Soil Pressures on a Retaining Wall------------ 120 

65 Grout Volume Required to Fill Radially Around Grout Point- 125 

66 Typical Grid Pattern for Waterstop Application ------ 126 

67 Typical Grouted Section for Strengthening Soil ----- - 127 

68 Schematic of Grouting for Metro System in Hanover, Germany 127 

69 Soil Grouting for Metro System in Hanover, Germany - - - - 128 

70 Schamatic Drawing of Pressure Meter Equipment- ------ 135 

71 Typical Results of a Pressuremeter Test- --------- 135 

72 Iowa Bore-Hole Direct Shear Test Device- --------- 138 

73 Goodman Jack for Borehole Testing - Soft Rock- ------ 139 

74 Clamshell Bucket Crane Used for Slurry Trench Construction 144 

75 Slurry Trench and Diaphragm Wall Construction- ------ 145 

76 Alternate Methods for Sealing Diaphragm Wall Panels- - - - 146 

77 Effect of Mixing on Hydration of Slurry (5% Bentonite) - - 151 

78 Gel Strength for Bentonite ---------------- 152 

C-l Grouting Operation in Progress -------------- 207 

C-2 Connection Between Station and Tunnel Through 

Grouted Soil 208 

C-3 Grouting Setup for Bridge Support- ------------ 210 

C-4 Tunnel Alignment Showing Intersected Chimney ------- 213 

C-5 Grout Point Locations in Chimney Section --------- 215 

C-6 Grid Pattern and Grouted Areas -------------- 217 

C-7 Schematic Equipment Layout ---------------- 218 

C-8 Schematic of Grouting for Sewer Support- --------- 220 

C-9 Washington Grouting Site----------------- 220 

C-10 Typical Excavation Under Grouted Area- ---------- 221 

C-ll Clay Encountered in Tunnel Excavation- ---------- 221 

C-l 2 Detail of Grout Pipe Installation and Seal 223 

C-l 3 Grout Injection Pumps and Flowmeters ----------- 224 

xi i 



Figure Page 

C-14 Schematic - Pumping System- ---------------- 226 

C-15 Schematic - Grouting Manifold - 227 

C-16 View of Grouting Area on Dam- --------------- 229 

C-17 Grouting Site 237 

C-18 Grout Distribution Manifold 237 

C-19 Grouting Toward Portal Opening- ___________ 239 

C-20 Tunnel Portal Opening 239 

C-21 Grouted Soil at Tunnel Face 240 

C-22 Sample of Grouted Soil 240 

D-l Piezometer Installations (Schematic)- ----------- 242 

D-2 Piezometer Test - Falling Head 243 

D-3 Typical Field Time-Lag Curve- --------------- 244 

D-4 Equipment for Laboratory Grout Distribution Test- ----- 245 

D-5 Test Probe Layout 246 



LIST OF TABLES 
Table Page 

1 Loss Coefficients for Valves and Fittings --------- 12 

2 Injectability of Main Types of Grout- ----------- 21 

3 Typical Mechanical Analysis of Soil ----------- - 57 

4 Examples of Calculated A/C Ratios ------------- 62 

5 Cost Comparisons of Grout ----------------- 68 

6 Properties of Currently Used Grouts ------------ 69 

7 Test of Grout Materials in Sand -------------- 79 

8 Relationship Between Failure Grouting Pressure and Effective 

Overburden Pressure- ------------------- 119 

9 Limiting Soil Penetration for Cement Grouts -------- 124 

10 Ben torn" te Slurry Properties ---------------- 149 

11 Bentonite Limiting Properties --------------- 150 

12 Summary of Grouting Operations Applicable to Tunnel 

Construction ----------------------- 159 

13 Evaluation of Grouting Operations in Tunneling- ------ 161 

C-l Test Boring Reports by Raymond Beneath Walt Whitman 

Bridge Overpass- --------------------- 212 

C-2 Hole Drilling Schedule 231 

C-3 Flow Rate Test 232 

C-4 Immersion Test- ---------------------- 232 

C-5 Visual Inspection Test- ------------------ 233 

C-6 Tests of Grouted Area of Dam 234 



xin 



LIST OF SYMBOLS 

A - cross sectional area of flow 

a - area of standpipe 

y - unit weight (or density) of soil 

Y d - dry unit weight of soil 

y - wet unit weight of soil 

Y - saturated unit weight of soil 

Y - unit weight of grout 
Y w - unit weight of water 

C - constant of integration 

C - uniformity coefficient 

c - soil cohesion 

D - pore diameter of soil 

D„ - diameter of borehole 
o 

d - diameter 

E - pressuremeter modulus 

e - void ratio 

G - specific gravity 

g - acceleration of gravity 

h - head of water 

h - initial head of water 
u 

hi - final head of water at time, t 
h - hydraulic head 

h, , - depth of water table below ground surface 

w 

L - rigidity index 



xiv 



i - hydraulic gradient 

i - minimum hydraulic gradient 

i - vertical hydraulic gradient 

K - dimensionless loss coefficient 

K' - Rankin stress ratio 

K - coefficient of earth pressure at rest 

k - coefficient of permeability 

k - coefficient of permeability for grout 

k, - horizontal permeability coefficient 

9 - velocity factor 

L - length 

M - mass 

u - coefficient of viscosity, or absolute viscosity 

N - ratio of grout viscosity to water viscosity 

n - soil porosity 

P - soil pressure force on retaining wall 

P f - end pressure of elastic stress range of pressuremeter 

P - grouted soil pressure force on retaining wall 

P. - limit or maximum pressure of soil using pressuremeter 

P - In situ horizontal stress 

P - grouting pore pressure 

Q - gravity of flow 

q - unconfined compressive strength of soil 

r - radial distance of grout penetration 

r - internal radius of pipe or casing 

S - sinking distance of grout in soil 

xv 



a - total soil stress 

a' - effective intergranular stress 

a" - effective stress due to buoyancy 

Oi - major principal soil stress 

a 3 - minor principal soil stress 

cry - major principal soil stress less hydrostatic 
pore pressure 

Ox - minor principal soil stress less hydrostatic 
pore pressure 

aij - soil shearing stress 

t - soil shearing stress at failure 

Tr - yield stress 

t - basic time lag in groundwater observations 

t - time 

t. - tensile strength between soil grains 

t - grout set time 

<j> - angle of internal soil friction 

u - soil pore pressure 

Au - grout pumping pressure 

V - volume 

V - volume of void space 

V - volume of solid particles 

V - radial flow velocity 
V x - Poisson's ratio 

W - weight 



xvi 



1. INTRODUCTION 



The construction of open trenches or tunnels for mass transit or 
highway systems has increased steadily in recent years. Many problems 
are encountered as excavations are made; among these are the intrusion 
of water, and the movement of the adjacent ground into the excavation. 
Grouting is one technique which can be used to help solve these 
problems. Grouting is the injection of a fluid material into the voids 
of the soil formation to stop or reduce water movements or to con- 
solidate and strengthen the soil. 

Grouting technology has not advanced to the status of a science, 
but remains as an art. This is due in a large measure to the secrecy 
which has surrounded the process for many years. Grouting specialists 
have been reluctant to share their techniques and grout material com- 
positions with others. As a result, construction contractors are 
dependent upon the grouting specialists to recommend proper procedures 
and specific grouts when their services were needed. 

In the United States, grouting is generally done on an emergency 
basis when water intrusion or running ground is encountered during con- 
struction. Remedial grouting is also used in Europe, but other types 
of grouting are used extensively and are frequently included in the 
original construction plans. 

On the other hand, European grouting organizations are normally 
large companies with complete foundation design and construction 
capabilities. Each company is capable of performing grouting, con- 
structing slurry walls, installing tieback anchors or dewatering. Some 
are also qualified to conduct site investigations and drive piling. It 
is not uncommon for European companies to be involved in all aspects of 
foundation work from the inception to the construction. Most of these 
companies have proprietary grout materials, developed by their own 
research laboratories, and are very open and communicative about their 
pumping equipment, downhole piping or accessories, techniques and job 
data. 

The technology for grouting in rock has been well developed in the 
United States and is generally well documented by papers and technical 
manuals (1)*. However, information on grouting in soils has not been 
readily available. This situation has been slowly improving over the 
past 15 years, due largely to the emphasis placed on soil grouting by 
the Geotechnical Division of the American Society of Civil Engineers. 
Even with this emphasis, however, most of the significant literature 
available on soil grouting has been produced by European grouting 
specialists. 



* Underlined numbers in parentheses identify references listed by like 
numbers in Chapter 14, beginning on page 169. 

1 



There are two general soil grouting procedures: fracture grouting 
and permeation grouting. Fracture grouting employs an injection pres- 
sure considerably higher than the overburden pressure for the purpose of 
opening cracks or channels in the soil deposit. The grout then flows 
along these channels throughout the soil and subsequently sets. This 
process not only forms lenses of grout but also can produce ground 
heave or lift; the grout also tends to follow any buried items, such 
as utility pipes, as it seeks channels of flow through more open soil 
layers. This type is not widely used. 

Permeation grouting is aimed at filling the voids in the soil de- 
posit with the grout fluid, displacing the water from the soil pores 
if necessary. The range of soils for this type grouting depends on 
the grout viscosity, but generally ranges in course sands or gravel 
for cement grouts; and soils up through fine sands are usually grout- 
able with some type of chemical grout. A low injection pressure is 
used to prevent movement of the soil or creation of a fracture. The 
grout will then set at a selected time to bind the soil particles into 
a solid mass. This report is concerned mainly with permeation grout- 
ing. 

This report summarizes present knowledge in grouting technology 
applicable to soils. It also forms a basis for future improvements in 
grouting materials, equipment and techniques. This report includes 
recommendations for checking a completed grout treatment for quality 
and effectiveness of the grouting, and provides recommendations for 
further research to improve soil grouting. 

This report includes sections on all aspects of grouting design 
and operational procedures in soil deposits, including the following: 

a. Grouting fundamentals, history and current practices. 

b. Grouting applications as waterstop barriers and for 
soil strengthening. 

c. Site investigation and determination of subsurface 
soil characteristics. 

d. Theory of grout injection and distribution. 

e. Grout material properties and their selection. 

f. Grouting equipment. 

g. Field testing of grouted soil. 

h. Grouting contracts and specifications. 

i. Slurry trench and diaphragm wall construction. 

j. Soil tieback anchors. 

k. Backpacking of tunnel liners. 

The Appendix includes a bibliography, case histories, test pro- 
cedures, sample specifications, patents pertaining to soil grouting, 
a list of grouting specialists, material suppliers and equipment 
suppliers, current grouting research, and a glossary of terms. 



2, GROUTING PRACTICES 



A. Grouting Fundamentals 

Grouting is a process in which a liquid is forced under pressure 
into the voids of soils, where the liquid will, in time, solidify by 
physical or chemical action. The injection of grout into the soil 
voids is used to block water movement, or to increase the strength of 
the treated material. Grouting is applicable mainly to cohesionless 
soils that are relatively permeable. 

The first step is a thorough site investigation to reveal soil 
structure and permeability. This information is essential to determine 
groutability, the best grout fluid and the applicable technique for the 
job. 

Grouting is normally accomplished by placing pipes in the ground, 
either vertically on a grid pattern or at varying angles to obtain the 
desired distribution, and injecting a fluid into the soil through the 
pipes at a pressure below the overburden pressure to fill the soil voids 
over a given area. Various grouts are available, including particulate 
types like cement or clay slurries and various types of chemical grouts. 
Chemical grouts can be designed to set quickly in the presence of flow- 
ing water or to set more slowly to allow greater penetration into the 
soil. Figure 1 shows a typical grouting job. 

On-site facilities are necessary to provide sufficient storage 
capacity for grout components, as well as equipment for mixing the grout 
and injecting it into the ground. Special pipes include rods which are 
driven into the ground, and plastic pipe with slots or holes which are 
grouted into boreholes for placing the grout at the desired levels. 
Provisions must be made to measure the flow of the grout into each pipe 
and the pressure at the point of injection. 

Grouting is limited to relatively pervious soils and to situations 
where the cost will not be a prohibitive factor. It is also limited to 
applications where the required strength is within the capability of the 
grout fluids available. 

B. Grouting Theory (For Solution Type Grouts) 

There are basic laws of fluid flow which relate to grouting. One 
definition of fluids is based upon its action under various types of 
stress. Fluids possess elastic properties only under compression. 
Application of infinitesimal shear or tension results in continual dis- 
tortion. As a result, pressure imposed on a fluid at rest will be 
transmitted undiminished to all other points in the fluid (2). 



GRTG. VAN 

PUMP & TANK 





Figure 1. Typical grouting job. 



4 



1. Physical Characteristics of Fluids 

The basic physical characteristics of a fluid are its unit weight, 
viscosity, and surface tension. All of these characteristics depend 
upon the molecular structure of the fluid. Unit weight (y) is the weight 
per unit volume, or 

Y=£ U) 

Specific gravity is the ratio of unit weight of the fluid to the 
unit weight of pure water. These properties all vary with temperature, 
so the temperature must be given when these properties are used in 
calculations. 

Viscosity, the resistance of a fluid to flow, is due fundamentally 
to cohesion and interaction between fluid molecules. As flow occurs 
these effects appear as a shearing stress between the moving layers of 
fluid. For nonturbulent flow, this stress has been found to be propor- 
tional to the rate of change of velocity perpendicular to the direction 
of flow. The constant of proportionality is known as the coefficient of 
viscosity. 

The apparent effects of tension which occur on the free surface of 
a fluid depend fundamentally upon the relative strength of the inter- 
molecular cohesive and adhesive forces. When adhesion is the predomin- 
ant force, the liquid will wet a solid surface with which it is in con- 
tact and rise at the point of contact; if the cohesion predominates, 
the liquid surface will be depressed at the point of contact. For 
example, water rises in a capillary tube and mercury is depressed at 
the point of contact. For tube diameters of one-half inch or more, 
capillary action is negligible, but when the diameter is small, as in 
the pores of fine grained soils, the capillary rise can be several feet. 

2. Fluid Pressure Under Static Conditions 

Before considering problems of fluids in motion, certain properties 
of static fluids should be understood. Fluid statics is concerned with 
fluid in which there is no relative motion between fluid particles. If 
no relative motion exists between fluid particles, viscosity can have 
no effect, and exact solutions to problems may be obtained by analytical 
methods without the aid of experimentation. 

a. Variations of Pressure with Depth in a Liquid 

The fundamental equation of fluid statics relates pressure, density, 
and vertical distance in a fluid. This equation may be derived readily 
by considering the equilibrium of a typical unit element of fluid having 
cross-sectional area A and length L, inclined to the vertical at an angle 
a, as shown in Figure 2. If the pressure at point M is denoted by P 19 
the force on that end will be P X A. Similarly the force on end N will be 
P 2 A. Similarly the force on end N will be P 2 A. The weight of the volume 




Figure 2. Pressure in a fluid. 



of liquid is yM, where y is the density of the fluid. Since the 
element is in equilibrium, the forces acting on it in any direction 
must be zero. Summing the forces along the MN axis, the forces 
perpendicular to the length L have no effect, since they cancel each 
other. The following equation is obtained 



P X A - P 2 A + yAL cos a = 
As L cos a = h 2 - hi , it follows that 

P 2 - Pi = y(h 2 - hx) 



(2) 



(3) 



Since a liquid is a substance which will continue to deform as long as 
any shearing stress exists in it, there can be no shear in a liquid at 
rest. By letting P x and hi be zero, and omitting the subscripts 2, we 
get 

P = yh (4) 

3. Pressure Measurement 

Pressures are measured and quoted in two different systems, one 
relative (gage) and the other absolute. If the measure shows pressure 
above absolute zero, it is called absolute pressure; that is, it includes 
the pressure exerted by the weight of the atmosphere. If the measure 
shows pressure either above or below atmospheric pressure, it is called 
gage pressure. This term is used because almost all pressure gages of 
any type register zero when open to the atmosphere, and when in use regis- 
ter only the difference between the pressure of the fluid to which they 
are connected and that of the surrounding air. 

The atmospheric pressure is also called the barometric pressure. 
Barometric or atmospheric pressure varies with altitude, and, at any 
given place, with time and weather conditions. Usually barometric 
pressure appears on both sides of an equation, and one negates the other. 
Thus the value of the atmospheric pressure is of no significance when 
dealing with liquids, and most pressures are recorded as gage pressure. 



a. Pressure Measurement Devices 

The Bourdon pressure gage and the mercury barometer are the usual 
devices for measuring gage and absolute pressures, respectively. A gage 
similar to the barometer is a piezometer. A piezometer is a very simple 
device for measuring moderate liquid pressures. It consists of a tube 
open to the atmosphere in which the liquid can rise freely without over- 
flowing. The pressure acting on the top of the column is atmospheric, 
and on the bottom, the pressure of the system; therefore, the height of 
the liquid column times the liquid density is the gage pressure per 
equation 4. A piezometer should have a tube larger than one-half inch 
in diameter to minimize capillary error. Connections should be made 
perpendicular to flowing fluids, and the tube should not project into 
the flowing liquid. The pneumatic type of the no-flow piezometer is 
being used increasingly for construction control. 

4. Flow of Water Under Pressure 

a. Fluid in Motion 

Fluid flow may be steady or unsteady, laminar or turbulent. Steady 
flow occurs in a system when none of the variables involved changes 
with time; if any variable changes with time, the condition of unsteady 
flow exists. For example, in a pipe leading from a large reservoir of 
fixed surface elevation, unsteady flow exists while the outlet valve is 
being adjusted. When the valve opening is fixed, steady flow occurs. 
Under the former condition, the pressures, velocities, etc., vary with 
time; in the latter case, they do not. During grouting, problems caused 
by unsteady flow occur only when valves are being opened or closed. 

If fine threadlike streams of colored liquid are injected into a 
large glass tube through which water is flowing at a low velocity, the 
colored liquid will be visible as straight parallel lines throughout 
the length of the tube. As the velocity of the water is increased, the 
lines first become wavy, then break down into numerous vortices beyond 
which the color becomes uniformly diffused. 

The first type of flow is known as laminar, streamline or viscous 
flow. The significance of these terms is that the fluid appears to move 
by sliding laminations of infinitesimal thickness relative to adjacent 
layers; that the particles move in definite and observable paths or 
streamlines; and also that the flow is characteristic of a viscous fluid. 

The second type of flow, where the color is uniformly diffused, is 
known as turbulent flow; the individual particles move in erratic paths. 
A distinguishing characteristic of turbulent flow is its irregularity. 
There is no definite frequency, as in wave action, and no observable 
pattern, as in the case of eddies. Thus, a rigid mathematical treatment 
of turbulent flow is impossible, so statistical means of evaluation must 
be applied. 



b. Rate of Flow 

The quantity of fluid flowing per unit of time across any section 
is called the discharge, or rate of flow. The rate of flow may be 
flow may be expressed in any units suitable. 

In the ideal case of a frictionless laminar flow in a straight 
channel, all particles move in parallel lines with equal velocities. 
The rate of discharge, Q, would be obtained by multiplying this uniform 
velocity, V, by the area of the cross section, A, of the flowing fluid, 
perpendicular to the direction of flow. 



AV 



(5) 



In the flow of a real fluid the velocity adjacent to the wall will 
be zero; it will increase wery rapidly within a short distance from 
the wall and produce a velocity profile such as is shown in Figure 3. 
If the flow is laminar, there is merely the velocity profile to con- 
sider; but if the flow is turbulent, not only will the velocity vary 
across the section, but, at any one point, it will fluctuate with time. 






m 



k 



Velocity 



Figure 3. Velocity profile 



The rate of flow Q in these instances may be calculated with lam- 
inar flow equation by calculating an apparent average velocity V for all 
particles. 

The law of continuity is an obvious statement that in steady flow 
without storage, what goes in at the upstream section must come out at 
the downstream section, so that 



YiAxVx = y 2 A 2 V 2 
For a liquid, y x will be equal to y 2 and 

AiVi = A 2 V 2 , or Q is constant 
8 



(6) 



(7) 



c. Energy Equation 

A body of mass, m, and velocity, V, possesses kinetic energy equal 
to mV 2 /2. Since weight equals mass times the acceleration of gravity, 
the kinetic energy expressed in terms of weight is WV 2 /2g, or simply 
V 2 /2g per unit weight. 

In the flow of a real fluid the velocities of different particles 
will usually not be the same, so it is convenient to use the mean 
velocity, V, and a factor, 9, such that for the entire section, the 
true average value is 

Kinetic energy per unit weight = 9(V 2 /2g) (8) 

The greater the variation of velocity across the section, the 
larger will be the value of 0. For laminar flow in a circular pipe, 
= 2; for turbulent flow in pipes ranges from 1.0 to 1.15; but for 
normal cases it is usually between 1.03 and 1.06. 

In some instances it is wery desirable to use the proper value of 
0, but in many cases the error in disregarding it is negligible. As 
precise values of are seldom known, it is customary to omit it and 
assume that the kinetic energy is V 2 /2g per unit weight of fluid. 

The laws of mechanics show that the potential energy of a weight 
W at a vertical distance z above datum is (relative to the datum) 
Wz ft-lb. If the weight is considered in units of one pound, the 
potential energy = z ft-lb/lb and E is the energy of the liquid 
associated with its temperature. The energy contained in each pound 
of fluid may therefore be expressed as (E + V /2g + z) ft-lb/lb. 

The work done on a fluid within an area by a weight of fluid 
entering the area would equal the work done by the fluid in an area on 
the fluid leaving the area. It can be derived that P/y is generally 
treated as the "pressure energy" of the flow. The energy equation 
thus becomes 

£- + ~- + k = Constant (9) 

Y 2 9 

The equation imposes another mathematical condition upon flow in 
a streamtube. It has already been shown (for a fluid of constant 
density) that the product of cross-sectional area and velocity is 
always constant along a streamtube. From the energy equation, it 
becomes evident that the sum of the three terms involving pressure, 
velocity, and elevation will also be constant at every point along 
the streamtube. This is known as the Bernoulli equation. 

Examination of the terms of equation 9 reveals that p/y and z are 
respectively the pressure and potential heads, and hence may be 
visualized as vertical distances. Pitot's experiments showed the 

9 



"velocity head", V 2 /2g, to be a vertical distance which could be 
measured by placing a small open tube in the flow with its open end 
upstream. Thus the energy equation may be visualized for liquids as 
in Figure 4, the sum of the terms being the constant distance between 
the horizontal (and therefore parallel) datum plane and the "total 
head line" or "energy line" (E.L.). The "pressure grade line" or 
"hydraulic grade line" (H.G.L.) drawn through the tops of the piezometer 
columns gives a picture of pressure variation in the flow: 

(1) its distance from the centerline of the 
streamtube is a direct measure of the 
pressure in the flow, and 

(2) its distance below the energy line is 
proportional to the square of the 
velocity. Complete familiarity with 
these lines is essential because of 
their wide use in engineering practice 
and their great utility in problem 
solutions. 



The energy equation gives further aid in the interpretation of 
streamline diagrams; equation 9 indicates that when velocity increases 
the sum of the pressure and potential head must decrease. 



Total head (energy) line 




Figure 4. Energy gradient. 
10 



In the usual streamline diagram, the potential head varies little, 
allowing the approximate general statement: "where velocity is high, 
pressure is low." Regions of closely spaced streamlines have been 
shown to be regions of relatively high velocity; the energy equation 
indicates that these are also regions of relatively low pressure. 

d. Friction Loss in Pipes and Fittings 

As a real fluid passes through a pipe, some mechanical energy is 
degraded into unavailable energy; there is a so-called "friction loss" 
or a "head loss" due to friction or viscosity of the fluid and the 
turbulent motion. No energy is actually destroyed. Some energy, how- 
ever, is transformed into a form which is not available for maintaining 
the flow; thus, from the point of view of the flow, it is "lost". This 
loss is present in grouting piping systems and can affect the actual 
grouting pressure since friction opposes flow. Let h represent this 
lost head. Then the general energy equation can be written as 

-h = (p a - Pi) / Y + (V. - V x ) / (2g * z. - z x ) (10) 
or 

h = (px - p a ) / y + (V? - VS ") ■/ 2g + (zi - z 2 ) (11) 

Each term in equations 10 and 11 is expressed in units of mechanical 
energy per unit weight of fluid flowing. The lost energy, h, can be 
stated in terms of foot-pounds per pound of fluid, or simply feet, or 
some other net unit of length. 

If the area of the pipe is constant, then by equation 7, v\ = V 2 . 
In this case, the pressure grade line is parallel to the energy grade 
line, or 

h = El + i x - h. + z 2 (j 2 ) 

Y y 

The head loss due to fittings is frequently expressed as K(v /2g), 
where K is a dimensionless loss coefficient and V is some characteristic 
velocity. Reliable head loss coefficients for many shapes of fittings 
have not been fully measured at the present time. So, real difficulties 
are encountered in trying to correlate experimental data, particularly 
measurements with different types of fluids. The values given in this 
section are to be regarded as approximations, because they are based 
on limited experimental results. 

Values for K in the equation below are shown in Table 1: 

Head loss = K ¥- O 3 ) 

2 g 



11 



Table 1 - Loss coefficients for valves and fittings. 



Valve or Fitting K Valve or Fitting 



Globe valve, wide open 10.0 Return bend 2.2 

Angle valve, wide open 5.0 Standard tee 1.8 

Gate valve, wide open 0.19 Standard elbow 0.9 

Gate valve, 1/4 closed 1.15 Medium sweep elbow 0.75 

Gate valve, 1/2 closed 5.6 Long sweep elbow 0.60 

Gate valve, 3/4 closed 24.0 45-degree elbow 0.42 



Source: The Crane Company 

These data emphasize the need to obtain pressure readings at the 
point of injection into the ground to provide the most accurate reading 
possible. 

5. Flow Through Soils 

a. Flow of Water 

The law for flow through soils is named after Darcy who demonstrated 
experimentally that the rate of flow is proportional to the gradient. 
Darcy' s law is written 

Q = kiA (14) 

or 

Q/A = V = ki 

The area A in these equations is the total cross-sectional areas of solid 
mass across which flow Q occurs. In equation 14, the term k is Darcy' s 
coefficient of permeability, which herein is called simply the 
permeability. This coefficient, which is the only permeability coefficient 
in common use in soil mechanics, is best defined as the constant of pro- 
portionality between the superficial velocity V and the gradient i, so 
k has the dimensional units of a velocity. The most commonly used unit 
for this coefficient in soil testing is cm/sec, or meters/sec. 

b. Flow of Viscous Grouts 

Viscosity is the term used to describe the nature of a liquid to 
flow easily like water (low viscosity), or sluggishly like heavy oil 
(high viscosity). Viscosity is due to the fundamental cohesion and 
interaction between fluid molecules. As flow occurs, these effects 
appear as a shearing stress between thin moving layers. 

12 



Viscosity has been found to be proportional to the rate of change of 
velocity in respect to depth for laminar flows. The coefficient of 
viscosity is the constant of proportionality in the relationship 
mentioned above. 

The dimensions of viscosity are lb-sec/ft 2 ; the metric counterpart 
is dyne sec/cm 2 , which has been given the special name of poises after 
Poiseuille who did some of the first work on viscosity. A centi poise 
is simply l/100th of a poise. Water at 68°F has a viscosity of one 
centi poise. 

Viscosity varies inversely with temperature. From calculations 
made by an equation developed by Bingham and Jackson (65), the decrease 
in viscosity caused by an increase in temperature is shown in Figure 5. 
In a viscous liquid the cohesive force between molecules is the 
primary property which controls viscosity. As the temperature of a 
liquid increases, the intermolecular bond decreases with a resulting 
decrease in the coefficient of viscosity u. 



1.8 



1.6 



1.4 



o 12 



a 10 

o 
o 

GA 

*S 0.8 



u 

*S 0.6 



0.4 



0.2 













































V Fahren 


tieit 






\cent 


r igrade 

























































20 40 60 80 100 120 

Temperature (deg.) 



Figure 5. Temperature effects on viscosity of water (32) 



13 



The viscosity of the water or fluid permeating the soil has an 
effect on the coefficient of permeability. If there is a difference 
between the viscosity of the water used to obtain the soil permeability 
coefficient originally and that of the grout, Cambefort (66) sets forth 
the following relationship which can be used to determine the perme- 
ability coefficient with the grout: 



9-U 



k 

~ k "g 

where 

k = soil permeability coefficient 
9 using grout with a viscosity u g 

k = soil permeability coefficient 
using water with a viscosity y 

or . = ky (15) 

The observed behavior of liquids under conditions of viscous flow 
can be explained by the hypothesis that the liquid moves in the form of 
concentric cylinders or shells, sliding one within the other like 
sections of a telescope. 

The flow rate for this condition is described by 

Q = NkiA (16) 

where 

N = viscosity ratio 

k = coefficient of permeability 

i = hydraulic gradient 

A = total cross-sectional area 
where flow Q occurs 

C. History of Grouting 

Grouting was first invented and used in 1802 by French engineer, 
Charles Berigny, who called it the Injection Process (3). He used 
slurries of clay and hydraulic lime, which were forced into subaqueous 
formations with a simple hand-operated pump to stop water flow. In 
1876, portland cement was injected beneath a dam in England under 
gravity head to seal fissured rock that was leaking. Between 1880 and 
1905 a group of mining engineers in the coal fields of Northern France 
and Belgium introduced injections of portland cement grout as an aid in 

14 



shaft sinking through fissured, water-bearing rock. They developed high 
pressure pumps and made improvements in the mixing and injection of grout, 
which remain the basis of much of the modern practice of rock grouting. 

The most difficult problems of water intrusion in shaft sinking are 
not found in the rock portions, but in permeable overburden deposits 
which overlie the rock. Attempts were made to grout these cohesionless 
soils with portland cement. This succeeded in the open, coarse-grained 
sediments, but failed in the fine-grained, dense sediments of low 
permeability. 

As the operators found that portland cement slurries would not 
penetrate the finer sand grains to achieve water shutoff, they added 
more water to the mixture to make it more fluid. This increased 
fluidity, but still did not permit the grout to permeate the sand 
because solid particles still in suspension were too large to enter 
the pore spaces in the sand deposits to effect water shutoff. Since 
successful treatment of soils with wide ranges of porosity is very 
desirable, the search continued for a liquid grout that had no solids 
in suspension, had a low viscosity and had the ability to set at a 
predetermined time. 

As early as 1887, a patent was granted to Jeziorsky for injection 
of soils by sodium silicate with a two-shot process (4J. The two-shot 
process consisted of injecting one chemical solution down a pipe to 
the desired depth, then following with an injection of another chemical 
which reacted with the first one to form a gel. This gel in the soil 
pores prevented the passage of water from the formation. A single-shot 
process patent was issued in 1909 for using a mixture of a diluted 
sodium silicate and a dilute acid as a grout material. This grout 
became a gel which could be used only for waterproofing. Additional 
patents were issued through the following years as attempts were made 
to improve these two processes. 

The greatest improvement in the two-shot process was developed by 
Dr. Hugo Joosten, a Dutch engineer, and a patent was issued to him in 
1926. By using sodium silicate for one solution, a precipitate of 
insoluble silica gel is obtained by the chemical reaction with a calcium 
chloride solution. This process has been used for sand consolidation 
since its introduction, yet it has inherent drawbacks. A close network 
of injection holes is required in order to obtain good penetration 
since the two solutions react immediately when they meet. 

The process of silicate gel formation is not completely understood, 
so it is impossible to state exactly how sodium silicate reacts with 
soils (5). However, sodium silicate can be used in soil stabilization 
mainly because it reacts with soluble calcium salts in water solutions 
to form insoluble gelatinous calcium silicates, and hydrated calcium 
silicates are cementing agents. 

The sodium silicate most commonly used is a solution known as 

15 



waterglass which has a silica/alkali ratio of about 3.22 and is sold at 
a density of about 41° Baume at 68°F or a specific gravity of 1.394. 
The raction obtained in the Joosten process using this silicate with 
calcium chloride would be: 

Na2Si3.22O7.44 + CaCl 2 + CaSi3.22O7.4a + 2NaCl 

Using a sodium metasilicate with calcium chloride would give: 

Na 2 SI0 3 + CaCl 2 ■*■ CaSi0 3 + 2NaCl 

Tn either case, a complex metal hydroxide silica gel is formed. 
The early uses of silicate grouts using the Joosten grouting process 
were for consolidation of sands in mine shafts and around footings, 
foundations, and piers. 

The Guttman process is a similar two-shot process which differs 
from the Joosten process only in the reduction of the viscosity of the 
sodium silicate before injection by the use of a suitable salt solution. 
This permits the grouting of finer-grained soil than the Joosten process. 

Figure 6 is a diagram of these two-shot processes which form a 
precipitate in the soil Drawings (a) and (b) show the injection of the 
silicate component as the pipe is driven by stages into the ground. 
Drawings (c) and (d) show the stage injection of the catalyst component 
(calcium chloride or a similar material) as the pipe is withdrawn from 
the soil . 



? 






(a) 



(b) 






fcr~ 
ft -1 

fit - -L 
EJ'-JKHlZ/; 



First Fluid 
Injections 



(c) 



(d) 



yy*^ 





^SgS 



Second Fluid 
Injection 



Figure 6. Diagram of Joosten grouting process, 

16 



Because of the large influx of people to urban areas, underground 
transportation systems were built in increasing numbers. This normally 
was done by open cut construction, except in areas where the route was 
in built-up areas which could not be destroyed. In these areas, 
tunnels of large diameter were bored. The relative closeness to the 
surface many times placed this construction in cohesionless soils, 
usually below the water table. Unsupported soils and water influx 
created serious construction problems of ground support. 

The need to stabilize foundation soils accelerated the development 
and refinement of chemical grouts, since the particle grouts could not 
permeate the finer soils to bind the particles together as needed for 
consolidation. 

About 1952 American Cyanamid Company developed a chemical grouting 
material called AM-9, which is composed of a mixture of acrylamide and 
one of its methyl derivatives. This water soluble grout material has 
a yery low viscosity (1-2 cp) which it retains until gellation occurs. 
It is widely used now, particularly for waterproofing applications. 
This grout can be mixed and injected in a single pipe since the set 
time can be controlled within limits as desired. 

In 1957, a process was developed by a European grouting firm, 
Soletanche Entreprise, in which a pure or diluted silicate was combined 
with an organic ester and various additives to produce a new grout 
material. Time of gellation could be controlled to permit one-shot 
injection. This development provided a material of relatively low 
viscosity which produced enough strength to consolidate cohesionless 
soils under structures, as well as to permit excavation without water 
or soil intrusion. Better mixing was provided than in the two-shot 
procedure, and this permitted the injection pipes to be placed farther 
apart. 

Other grout materials have been discovered through continual 
research. Among these are lignochromes or lignin based materials, 
phenol formaldehyde and various resins and combinations thereof. 

The original injection tubes were simply pipes with the lower end 
covered to prevent soil from entering and plugging the pipe as it was 
driven into the soil; when the pipe was driven to desired depth, the 
end covering was ejected by pumping water or grout and the injection 
of grout was then begun. This system, although now more highly 
developed, is still used for placement of grout down to depths of 
50 to 60 feet. 

Figure 7 shows a schematic diagram of the equipment setup for a 
grouting job which might be typical of that followed by many grouting 
companies. 



17 




TANK 
NO. 1 




VALVE H 



PUMP NO. 1 



FLOWMETER 



TANK 
NO. 2 



% VALVE 

AIR MOTOR DRIVE 



PUMP NO. 2 
FLOWMETER 



DRIVE ROD 
OR PIPES 



n 



2 



PRESSURE GAGE 



TORRES f% p4 

PRESSURE CHECKX VtX}-^' P q 

GAGE T^ ALV ^ ALVE °3 R 4 

i m fl> n 3 
Pi R2 



pi 



pi 



fl, 



Figure 7. Schematic of job layout, 



18 



D. Current Practices 

Generally, the practices of grouting companies are basically similar 
in the objectives for grouting and in the techniques used; differences 
in the operations are found in the mixing and injection systems and in 
the grouts used. These areas of practice will be discussed in this 
section. 

The objectives of grouting are mainly to stop running ground or 
water leakage, to consolidate soil so it will stand up during excavation, 
to strengthen granular soil under foundations, and to level slabs or 
structures. The objectives and accomplishments of grouting have been 
accepted by construction companies and Metro system management in Europe 
to the extent that it is common practice to include grouting as a part 
of the construction procedure. This is not true in the United States, 
where grouting companies are generally called to a job when running 
ground or water intrusion halts construction process. 

When grouting is included in a project, the American way is to 
write some type of specification which must be followed by the contractor. 
In Europe, the grouting company is given the opportunity of proposing 
how they would conduct the work to achieve the aim of the owner, and 
then quote a cost for that work. This might include several types of 
water or ground control, all of which could be done by the same company. 
This could include dewatering, slurry trenches, diaphragm walls, tieback 
anchors or grouting. Figure 8 shows cut-and-cover construction for a 
Metro system in a French city where one grouting company has built slurry 
trenches and diaphragm walls. Subsequently, they grouted extensively 
between the walls to waterproof and strengthen the soil below the pro- 
posed tunnel structure to prevent water intrusion when excavation is 
made between the diaphragm walls. 

Techniques used in Europe are generally similar to those used by 
American grouting contractors. The grout is mixed and injected through 
pipes driven into the ground or plastic pipes lightly grouted into 
drilled holes. Permeation type grouting is used in most cases; the 
amount of grout injected is usually 30-35% of the soil volume, although 
one European company frequently uses as much as 50% grout. One variation 
in technique, found in both the United States and Europe, is the use 
of cement or cement-bentonite grouts ahead of the chemical grouts to 
fill the larger voids, thereby reducing the amount required of the more 
expensive chemical grout. Some companies do this as standard practice 
in an effort to reduce the cost; others use cement only if the soil 
investigation shows that the permeability is high enough to permit its 
use for permeation grouting. This would be in coarse sand or ground 
with a permeability greater than 10~ 2 m/s, according to Table 2. 

The mixing and injection systems vary considerably, both here and 
abroad. A commonly used system includes a piston type, air operated 
pump with separate mixing tanks. Figure 9 shows a dual pump so con- 
structed that two streams can be moved in equal volumes in a two-stream 

19 




Figure 8. Slurry trench, diaphragm wall and grouting on French job. 




Figure 9. Dual piston type grouting pumps and mixing tanks 

20 



OO 



4-> 

3 

o 

S- 

cr 



</> 
cd 

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21 



grout system. Figure 10 shows the setup for a grouting job to consoli- 
date running sand, with the pumps located in a cut-and-cover construction 
site on the Virginia coast. Injection is made by a hand-held manifold 
through holes drilled in the wood lagging walls as shown in Figure 11. 

Larger jobs involve the use of storage tanks for the grout components, 
track drills for drilling holes to place slotted plastic pipe, and a 
larger trailer or portable building to house the pumps and related equip- 
ment. Figure 12 shows such equipment on a site in Washington, D.C. 
Figure 13 shows the trailer interior with the electric-powered, 
progressive cavity type pumps driven through a gear box to provide pro- 
portionate delivery of the grout components. Flow meters display the 
volume of grout injected by each pump. 

The European grouting companies have more sophisticated systems for 
their grouting operations than their American counterparts. Each company 
seems to have different styles of pumps, varying from small gear type to 
larger piston pump, but all are mounted in trailers or in portable build- 
ings which are moved from job to job. Pumps are driven by air motors or 
electric motors. 

Injection is accomplished by American contractors primarily through 
drive rods or, plastic pipe set in boreholes. Most European companies 
use the tube-a-manchette system invented by Soletanche Entreprise, which 
now seems to be readily available to all companies. In addition, one 
Dutch grouting company uses a single tube-a-manchette element at a 
desired depth connected to the surface by a small, flexible plastic tube 
as shonw in Figure 14. Six elements can be placed at one time on a 
spacing of one meter (3.28 feet), using a special machine which holds 
the plastic tubes inside steel pipes for placement. Figure 15 shows 
the machine placing the six elements on a job near Amsterdam, Holland. 
Withdrawal of the steel pipes leaves only the plastic tubing extending 
above the ground ready for grouting as shown in Figure 16. This is 
used to place a single grout layer about one meter thick. 

The grouting companies of Europe have their own research labora- 
tories to perform research on grouting materials and processes. As a 
result, these companies use a variety of grouting materials. The pre- 
dominate base component is sodium silicate, but the reactant used with 
the silicate varies between companies. The American companies primar- 
ily use grout materials which have been developed by the chemical 
manufacturers. Silicate type grout has the largest usage, primarily 
due to its lower cost and availability, but significant amounts of 
AM-9 polymeric water gel, formaldehyde and lignin based grouts, are 
also used. A detailed discussion of the grout materials is given in 
Chapter 5. 



22 




Figure 10. Small grouting job in cut-and-cover construction 




Figure 11. Grouting to consolidate sand behind wood lagging, 

23 




Figure 12. Large grouting job site and equipment. 




Figure 13. Van mounted grout pumps 



24 







Figure 14. Packer element and connector tubing used in Europe, 




Figure 15. Machine for placing packer element and connector tubing, 

25 




Figure 16. Grouting tubes in place for grout injection. 



E. Evaluation of Current Grouting Practices 

Grouting is used only occasionally in the United States, but it is 
used very extensively in Europe. The American companies are small firms 
with limited capability and equipment, while the European companies are 
complete foundation specialists with research laboratories and 
personnel capable in many disciplines. The European companies began 
about 40 years ago when construction of dams became widespread through 
Europe and Asia. When the governments initiated this work, they looked 
for private companies to conduct foundation investigations. This 
brought about the development of the foundation company in Europe with 
diversified capabilities, including grouting. During the past 15 years, 
urban transportation work increased so the companies applied their 
expertise to the tunneling operations inherent in the construction of 
Metro systems. Grouting was considered a valuable stabilization method 
for open cuts and tunneling, so it was given primary consideration in 
planning of the Metro systems. The private companies were used exten- 
sively to help in the planning work for the systems. This resulted in 
the larger, diversified companies in existence today. 

In contrast, in the United States, the expertise for this type of 
work was developed by government agencies, such as the Corps of 
Engineers, Bureau of Reclamation, etc., who built their own organi- 
zations to perform the grouting work on dams. Consequently, when the 

26 



work began on a large scale for underground transportation, there were 
no grouting companies with complete foundation design and construction 
capabilities. There was very little incentive for the development of 
such organizations, since grouting was not given consideration as a 
method for construction and its use was limited to emergency situations. 

In the United States, fixed price contracts are the general 
practice for construction projects. With this practice, it is essential 
that the prospective bidders be told the exact conditions of the soil 
where a tunnel or excavation is to be made, especially if grouting 
applications are involved. Since the site investigation many times is 
not thorough, it becomes very difficult to write a specification setting 
forth end conditions. In addition, there are no economical means for 
determining soil conditions after grouting. Therefore, the few specifi- 
cations that have been written usually specify a compressive strength 
for the grouted soil and the guide lines for conducting the grouting. 
Confirming the results has been very hard, and usually is attempted by 
drilling a few boreholes at random across the grouted area. 

In contrast, European practice is to send out a "tender" to 
prospective contractors for a particular construction job, for example 
some portion of a Metro (subway) system. The owners permit the 
foundation companies to make a proposal on their method to accomplish 
the job. Many contracts are then made by negotiation with the company 
submitting the most satisfactory proposal for the job. 

Generally the payment for jobs in Europe is made on the basis of 
square meters of surface grouted or cubic meters of soils grouted, 
while in the U.S. payment is usually based on gallons of grout pumped. 
The European companies furnish a recorded chart of pressure and flow 
rate information on each hole grouted, using a grout material which 
has known strength qualities. From the owner's standpoint, this seems 
to be a satisfactory way to handle the grouting. Costs are presently 
(1975) on the order of $150.00 to $200.00 per cubic meter of soil 
grouted in European Metro systems, as compared to about $130.00 per 
cubic meter in the United States. 



27 



5. GROUTING APPLICATIONS 



Grouting has been used successfully in the earth to stop groundwater 
flow, to strengthen soil deposits, for compaction or mud jacking, for 
tieback anchor grouting and in backpacking of tunnel liners. 

A. Waterstop 

The use of grout to prevent water movement is the oldest usage for 
grout. Water movement is stopped or greatly reduced by making a section 
of soil relatively impermeable with grout across the area of the water 
flow. 

1 . Dam Foundations 

The use of portland cement grout curtains in foundations of dams 
has been well documented in literature pertaining to rock grouting. 
This application has generally been successful over the past 50 to 60 
years in stopping or greatly reducing water movement through fissures 
and cracks of the rock foundations. The use of cement grouting for dams 
and related applications in rock is well documented in manuals published 
by the Corps of Engineers (la,b,c), the Bureau of Reclamation (If) and 
the Departments of the Army and Air Force (Id). Therefore, further 
discussion will be limited to grouting in soil formations. 

In recent years, dams have been constructed on beds of alluvial 
soils. Portland cement grouts were still used for grout curtains where 
the alluvium was coarse enough to permit the grout to penetrate. Chemical 
grouts (usually silicate type), and clay grout were used for the finer 
sand layers. A number of jobs using cement, clay and/or chemical grouts 
are described by R. Chadeisson (6) for dams in Algeria, Germany, Canada, 
France and Hong Kong. The permeability of the grout curtain underlying 
the future Mattmark Dam in Switzerland was reduced using cement and 
chemical grouts (7J. Soil deposits as deep as 100 meters (328 feet) were 
grouted in four stages. Clay-cement and bentonite grouts were used for 
the first three stages, reducing the overall permeability to 10" 1 * cm/sec. 
A fourth grouting stage using an aluminate-sodium silicate grout further 
reduced the permeability of the grout curtain to 6 x 10" 5 cm/sec. 

A unique method of placing a grout curtain was devised by a French 
contractor, Etudes et Travaux de Foundation (67). A row of steel piles 
is driven into the ground by a pile hammer. As the eighth pile is driven, 
a pile extractor begins pulling the first pile placed. Each pile contains 
a grout tube inside the flange. As the pile is removed, cement grout 
is pumped into the void left by the pile. The result is a solid cement 
curtain with the shape of the piles as shown in Figure 17. This method 
has been successfully used in the placement of a curtain through a 
highly permeable gravel bed under earth-fill dikes near the Danube River 
in Germany. 

28 



Extraction 
A 



Grout in 



Grout tube ■ 
in beam fillet 



3i 






Finished 

grout 

curtoin 



Curtain 
being 
injected '. 



m 




Beam 
driving 
~**in. 

Ground 
level 



VTTPVf 




foundation 
rock 



Figure 17. Pile-type cement grout curtain, 
source: ENR, April 25, 1963 



2. Cut-and-Cover 

Cut-and-cover tunnel construction is being us 
ditions permit for Metro underground systems both 
and Europe. Mery little grouting has been done fo 
cut-and-cover construction in the United States, 
cut-and-cover construction for a Metro system now 
France utilizes diaphragm walls and sheet steel pi 
performed between the walls prior to excavation to 
from entering the excavation (see Fiqure 18). For 
of soil from 8m to 16-1 /2m (26.25 to~54.14 feet) b 
grouted between the diaphragm walls using cement a 
The drawing in Figure 18 shows the details for thi 



ed where surface con- 
in the United States 
r water control during 
On the other hand, the 
being built in Lyon, 
ling, with grouting 
prevent the water 
this job, the volume 
elow ground level is 
nd chemical grouts, 
s job. 



A type of diaphragm wall now being used by one company in European 
installations is the prefabricated panel called "Panosol" (68). With 
this system, the slurry used to fill and hold open the trench contains 
Portland cement and a retarder additive with the bentonite to obtain a 
set after several days. Figure 19 shows how the grout strength must 
increase with time to satisfy the following requirements: 



29 



SHOPS 

& 
BLDGS. 



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SIDEWALK 
CONCRETE DIAPHRAGM WALLS 



SHOPS 

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BLDGS. 



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APPROX. 
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1.5 M 



CHEMICAL GROUT 



S> 



6 M 



CEMENT GROUT 



r-.75 M 
'"■^CEMENT~&~CHEMiCAr GROUT ^~ 



! 



Figure 18. Cut-and-cover grouting for Metro system in France, 
source: Soletanche Enterprise - Paris, France 



30 



(a) Remain fluid during excavation and placement 
of wall elements. 

(b) Acquire sufficient resistance in several days 
to permit excavation of area beside installed 
wall . 

(c) Permit grout removal from inside of wall after 
excavation. 

(d) Obtain final strength equivalent to soil 
strength. 



kg/cm 5 
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? 

o 

u 

o 



0.2 



Maximum resistance for cleaning joint 




Max. resist, for drilling 
and equipping 
trench 



Minimum resistance for future drillings 



Time ( in days ) 



Figure 19. Strength curve of special grout used with prefabricated 
wall installations (68). 



The prefabricated wall elements of reinforced concrete are made in 
several shapes and appearances. These may include tongue and groove, as 
shown in Figure 20, or T-shaped or H-shaped beams with slabs between 
The grout in the trench fills the joint between the wall elements to 
provide the necessary seal. 



31 




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32 



On a job for a Metro station in Holland, chemical grouting was per- 
formed on a 1m (3.28 ft) thick section at a depth of about 9 to 10 meters 
(29.5 to 32.8 feet) using a special one-element packer (see Figures 14, 
15 and 16). When this area is excavated, a thickness of sand sufficient 
to hold the hydrostatic head of groundwater is left over the grouted 
section. 

3. Tunnel Boring 

One application for grouting in tunneling is in reducing the per- 
meability of water-bearing sand so that the tunnel can be excavated 
using compressed air with lower air pressure (8). Another application 
was in construction of a trunk storm sewer which required manholes 
extending down through a water-bearing sand. Entrance of water into 
the tunnels was prohibited by grouting the sand around the manhole as 
the lining was sunk into place through the sand (9). 

In the Paris transit system, the tunnel crossing the Seine river 
used immersed caissons. A grout curtain was constructed prior to 
immersion from a floating barge to prevent the sand underlying the 
piers of the Neuilly Bridge from flowing into the excavation for the 
caissons (10). This is shown in Figure 21. . 



SEINE River 




Figure 21. Grout curtain protecting bridge piers (1_0) 



33 



4. Remedial Grouting 

Remedial grouting is that performed on completed structures when 
leakage occurs. A common application is repairs to leaking earthen dams. 
On a dam in Illinois, seepage through the downstream toe of the dam was 
blocked by a chemical grout, then sealed using cement and bentonite grout 
(IN). An Oklahoma dam was grouted with chemical grout to reduce water 
leakage through the earthen dam. A case history of this dam is included 
as Exhibit G, Section C of the Appendix. Leakage into metal or concrete 
structures through joints, bolt holes or cracks can also be repaired 
using chemical grout injection. This is fairly common for concrete 
tunnels and mine shafts. Underground missile tunnels of corregated 
steel have also been repaired with chemical grouting after welding and 
sealing compounds had failed (12). 

5. Slurry Trench 

A slurry trench is a narrow trench which is filled with a bentonite 
slurry as it is excavated to stabilize the walls of the trench. The 
slurry trench can also be used to prevent migration of groundwater in 
conjunction with applications discussed above. A successful job has 
been done southwest of Memphis, Tennessee by using a slurry trench as 
a grout curtain. Slurry was replaced in the trench with a dense, 
impermeable clay soil, which was packed in place to form a waterstop 
barrier. This resulted in an estimated saving of $1 million by per- 
mitting dry excavation for a large pumping station. The slurry trench 
and diaphragm wall system is widely used in Europe, particularly in 
underground construction next to existing structures. 

B. Strengthen Natural Soil Deposits 

This application involves permeation of the soil voids with a grout 
material to replace the air or water, cementing the particles together 
to give increased compressive strength. It has been used in construction 
of subways in built-up urban areas to: (a) strengthen soil formations 
under buildings adjacent to the excavated areas, (b) to solidify soil 
for tunneling support, (c) to strengthen foundation soil under bridge 
piers and (d) to prevent loss of ground during excavation of tunnels or 
other areas. This type of grouting has been and is being used in most 
of the Metro (subway) systems in Europe, and it is now being used on an 
increasing scale in the United States and other countries constructing 
underground transit systems. 

1. Under Footings and Foundations 

Grouting to strengthen soil deposits under footings and foundations 
is normally accomplished by setting injection pipes from the surface at 
an angle to reach the soil under the building foundation or bridge foot- 
ings. One such job was performed in Cleveland, Ohio to strengthen the 
soil under two bank buildings so the soil could be completely excavated 
between the buildings without any damage to either structure. A silicate 

34 



type chemical grout was injected into the soil under the footings of the 
two structures. This permitted excavation to extend as much as eleven 
feet below the footings of the two bank buildings without any movement 
of either structure. The soil was solidified sufficiently to be used 
as forms for the concrete foundations of the new buildings (13). Another 
example of strengthening the soil under an existing footing is shown 
in Figure 22, where the soil was consolidated under the footings of a 
hospital in London to prevent settling when nearby excavation was made 
(14). 




Injection pipes 



Scale h" = lft 



W orkshops 



Existing ground level I 46.1 




G.W.L 



Courtesy Soil Mechanics, Ltd, 
Figure 22. Grouting under footing of British hospital. 



Soil around a large sewer line was grouted with cement grout followed 
by chemical grout. This was done to provide support for the line as two 
tunnels of the Washington, D.C. Metro system was bored under the line. 
This job is detailed as Case History E in Section C of the Appendix. 

Grouting under footings for strengthening the soil is very prevalent 

35 



on the continent of Europe. The writers observed extensive grouting for 
a Metro system in Hanover, Germany. A silicate type chemical grout was 
being used under building foundations located adjacent to and above the 
proposed tunnel of the Metro system to prevent any settlement of build- 
ings during tunnel excavation. 

2. For Tunnel Excavation 

Perhaps the most common use of grouting on a larger scale is the 
consolidation of soil to prevent running ground or water intrusion 
during tunnel or shaft excavation. Grout is injected either from the 
ground surface, from a gallery (pilot tunnel) or into the face of the 
tunnel within the excavation. 

In New York City, chemical grouting with formaldehyde and acryl amide 
types was used in the construction of a large sewer interceptor tunnel 
because mixed face conditions (interlayered permeable and impermeable 
soils) were indicated in preliminary surveys. This conditions would 
permit water and ground intrusion where permeable layers were encountered. 
The use of compressed air would have been expensive and inconvenient, 
so grouting was selected as the construction method. Initial grouting 
was done from the tunnel face using acryl amide. Subsequent grouting was 
done from the surface ahead of the face with formaldehyde grout to 
achieve a successful jobQ5). 

Grouting was selected as the most feasible solution in the con- 
struction of eight junction corridors between four tunnels into an 
underground station located under the Hamburg, Germany, State Railways 
Central Station. The soil was consolidated and strengthened from the 
excavated tunnels so that the corridors could be excavated by hand under 
the roof of treated ground without any major difficulties (16). Figure 
23 shows this grouting procedure. 

Another soil strengthening application reported was grouting for 
the underground railway in Munich, Germany (16). The purpose was to 
strengthen the soil and to reduce the permeability in water-bearing sand 
and gravel to permit excavation with automatic shield under reduced air 
pressure. As shown in the upper portion of Figure 24, most of the grout- 
ing took place from cellars of the buildings above. A bentonite cement 
grout was used first to fill the larger voids; then, a silicate base 
grout was injected to fill the smaller voids. Grout holes were also 
drilled through the invert canal or from working shafts to complete the 
job, as shown in the lower view looking into the tunnels. 

During construction of the Auber Station in the Paris Transit 
System, grouting was the key method of construction rather than an 
auxiliary process of remedial grouting (10). To accomplish the grout- 
ing properly, three work tunnels were constructed parallel to the Auber 
Station to perform the grouting from underground. A top gallery was 
constructed first, then the side areas of the station were grouted to 
permit dry excavation of the other two working galleries and to obtain 
a seal of side walls for the main tunnel as shown in Figure 25(a). 

36 



Station tunnels 




+ 2 30 



Sand 



Tertiary "*- " 

clay "*- " 



Cross section 




+ 2 30 



Cast iron 
segments 



-3 00 



- 4 00 



Temporary jacks 



r 

Y / 



^ Construction 
of passage 




Figure 23. Hamburg (Germany) subway grouting (16) 

37 




Tertiory 
clay 






Fill 

Sandy 
and 

gravelly 
alluvium 

Tertiary 
clay 




♦ 507*9 



Figure 24. Munich (Germany) expressway grouting (16) 

38 



KUt AUBIK 



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w?2 









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i.-o-.o- .:?.» 3 »'/,'. , o.-„-. .,»-\- . /'.o;o 



^5 



(b) From Soletanche Entreprise 
Grouting from galleries in Paris Metro system. 



Figure 25, 



39 



Grouting was then used to seal the floor, the lower part of the side 
wall area, and the soils surrounding the arch of the station. This 
treatment was made from all three galleries as shown in Figure 25(b). 
The successful operation here was important because the station was 
located under historical buildings which could not be disturbed. 

While excavating a tunnel on the Washington Metro system near RFK 
Stadium, cohesion! ess sand and gravel were encountered which produced 
a running face and ground settlement as shown in Figure 26. A grouting 
program using silicate base chemical grout was initiated to stabilize 
the face from the surface before excavation. Grouting was successful 
in consolidating the soil to allow excavation without further loss of 
ground. A detailed report is given as Exhibit H in Section C of the 
Appendix. 



ROUND ■£ -yC 

• • • \ M m / § * I 

. ... • • . ...... \ t « ' \ // ',/ , 

•• •* ******** t. m 

...... 40- •••;. . •.!>-•: ;;^' 

X. ... ***.'* + 



TUNNEL 



<'-'/• 




Figure 26. Running ground encountered in tunneling. 



3. In Cut-and-Cover 

A major use of grouting and slurry trench construction in cut-and- 
cover construction is for water shutoff. In Lyon, France, grout was 
used to strengthen the soil to withstand the hydrostatic head below the 
excavated portion between the diaphragm walls. Details were given in 
Section A. 2 on pages 29 and 30. 



40 



C. Compaction Grouting 

Compaction grouting, in contrast to permeation type grouting, 
consists of intruding a mass of viscous cement grout into the soil to 
fill voids and to compact the soil by pressure (17). The process is 
most often used to compact fine grained soils and to raise structures 
which have settled (18). Its use below 20 to 30 feet (6 to 9 meters) 
is not economically feasible; nor is it effective in near-surface soils 
where the overlying restraint is small. Compaction grouting is used to 
stabilize soil under residences and light buildings; it has also been 
used to level concrete slabs and pavements, to raise tanks and structures 
which have settled, and to level machinery bases to stop vibration. It 
has also been used under footings of structures which have been built 
on uncompacted fill. Caution must be observed to prevent excessive 
uplift of structures, or when grouting in an area where underground 
pipes may have been ruptured by excessive settlement. 

A heavy compressor in a northeastern industrial firm was vibrating 
so badly that the plant operation was endangered by rupturing lines. 
The voids beneath the compressor base were filled with cement grout, 
and the soil was compacted to provide more resistance against vibration. 
The subsequent reduction in vibration was 90% and the movement was no 
longer visible (]_?). 

A large storage tank in the Midwest area had settled, but it was 
lifted back to near normal conditions by compaction grouting (20). 
Grout holes were drilled around the periphery of the tank, and viscous 
grout was injected through vertical pipes as shown in Figure 27 to 
form a wall of grout around the circumference of the tank. The grouting 
to level the tank was then made through pipes at a 30-degree angle to 
place the grout inside the grout wall and under the tank as shown in 
the lower drawing of Figure 27. 



D. Tieback Anchorages 

The use of tieback anchors is widespread both in Europe and in the 
United States. The technology is well defined through many published 
papers (see Bibliography), and there are many competent companies who 
design and install tieback anchors. These anchors are installed in both 
rock and soil to provide lateral support for walls used in ground 
support walls. In the United States, ground support by soldier beam 
and wood lagging walls are most common and anchors are used in some 
cases. Anchors are also used with sheet steel piling and concrete 
diaphragm walls. Figure 28 shows a soldier beam and lagging wall where 
part of the wall is supported with tieback anchors. The tieback anchor 
system provides an open, uncluttered work site. 

In open cut construction in Europe, concrete diaphragm walls are 
used extensively, and sheet steel piling is used to some extent. Tie- 
backs are used with both types of walls. The grout used in the tieback 

. 41 



FROM 
PUMP 








Figure 27. Schematic of compaction grouting to level tank (20) 



42 




Figure 28. Open cut construction with both strut bracing 

and tieback anchorages. 



anchorage is generally conventional portland cement grout. Figure 29 
shows workmen placing an anchor in a sheet steel wall on a cut-and-cover 
construction job in Lyon, France. 

Prestressed rods or cables are normally used as tiebacks. The 
location of the grouted anchor zone is dependent upon the soil properties. 
A theoretical "failure plane" will extend up from the bottom of the wall 
at an angle of 30° to 35° with the vertical (see Figure 30). The 
grouted anchorage must be beyond this "failure plane" to be considered 
in a safe location. The length of tieback which passes through the 
theoretically nonbearing soil is greased or wrapped with plastic to 
prevent bond with the surrounding soil when the anchorage section is 
grouted. Figure 30 gives a typical detail of an earth anchor tieback 
which uses a steel rod for the stress member (21). Holes are normally 
drilled about 20° to 30° below horizontal. Bore size varies according 
to the soil and may be from 3-inch diameter (7.5cm) for granular soils 
to 12-inch diameter (30cm) in cohesive soils. The length of the grouted 
section is calculated for the desired load; in some cases the section to 
be grouted is enlarged by underreaming or postgrouting to provide greater 
holding strength. Design load per anchor varies from 50 kips to 100 kips 
in the United States. Anchors are normally stressed to a proof load, 
then backed off to the design or working load (22). Detailed information 



43 




.**_ *..* 



Figure 29, 



Placing tieback in sheet steel wall. 



WASHER PLATE 
BEARING WASHER 



TOOTHED 
HEX LOCKING 
NUT 




TIP OF H-PILE - ELEV 29 t 



Figure 30. Typical detail of earth tieback anchor (21) 

44 



is given in Report No. FHWA-RD-75-130, April 1, 1976 by Goldberg-Zoino 
and Associates, Newton Upper Falls, Massachusetts. 

Costs for using tieback anchors are higher than for using struts. 
However, the anchors can be made permanent, and they provide an open 
work area between the walls. 



E. Backpacking Tunnel Liners 

Backpack grouting in modern tunnel construction refers to filling 
the annular space between a tunnel bore and the tunnel lining (or rings) 
with portland cement. The tunnel bore is somewhat larger than the out- 
side diameter of the tunnel lining. After excavation of about four feet 
(1.22 m), or the length of one ring of lining, the lining is put into 
place. The rings (about 1 meter long) are erected by bolting the 
sections together and to the last ring installed. Ring grouting is 
started immediately after the ring is in place. Most of the rings are 
iron or steel and contain plugged holes around the periphery through 
which grout can be injected. Grouting is accomplished using a sand, 
cement and water slurry. The composition used recently on a job in 
Brazil was about 63% sand, 21% cement and 16% water. 

Backpack grouting is accomplished as quickly as possible after 
ring placement to fill the space behind the ring before the soil 
can fall into the space and cause settlement on the surface. Grouting 
injection is begun at the bottom and progresses up the sides to the 
top. Injection points are moved up as the grout appears in the hole 
next higher up the side, or as it leaks into the tail of the shield. 
Pump pressure is kept as low as possible to move the grout without danger 
of fracture. A final grouting stage is done after grouting to top of 
ring using a neat cement grout with one part of cement to one part of 
water by weight. 

The grout should be mixed and ready for use as each liner section 
is erected. The setting time should not be any longer than necessary to 
mix and place the cement. On a tunnel for the Sao Paulo, Brazil subway, 
a cycle time for machine tunneling to advance, erect and grout a one 
meter ring was 2 hours and 10 minutes. 

F. Alternate Use of Freezing 

Freezing of ground for mining and construction applications has 
been in use for over a century. It is adaptable to any size, shape or 
depth of excavation and the same equipment can be used in each appli- 
cation. It is best suited for use in soft ground for excavations deeper 
than 7 meters (23 feet). Excellent reviews of frozen ground construction 
techniques have been presented by Khakimov (23), Sanger (24), and 
Shuster (25). 



45 



Freezing will probably be used increasingly in the Soviet Union. 
It is used in Europe also, but only to a small degree in the United States 
It is expensive and is usually a last resort. There are only one or two 
companies in this country that have the equipment and capabilities to 
perform freezing operations. One company has two 100- ton refrigeration 
units, driven by electric motors, which they use in their work. 

Figure 31 shows five basic alternate freezing approaches. All of 
these approaches consist of a primary source of refrigeration and 
secondary distribution system to circulate the coolant or refrigerant 
in the ground. 

The freezing approach used on most projects today is the Primary 
Plant and Pumped Loop Secondary Coolant System. This system uses a 
conventional one- or two-stage ammonia or freon refrigeration plant. 
Its distribution system typically consists of an insulated coolant 
supply manifold, a number of parallel connected freezing elements in 
the ground with inner supply and outer return lines and an insulated 
manifold. 



~L-iQ' 11 ^@3 




2 

i 

c 



NO PLANT, 

LXPtNOAbLE 

.SOLID PiEFftlGEPiANT 



G 







NO aANT, 
CXPEKOA&LE LIQUID 
PiEFWGEPiANT 



eCLlQUEFACTIOM 
PLANT WITH 
IN-<&ITU CASCADED 



PWMAPiY 

plant wrru iN-erru 

EV^POIhATOh 



PNMAftY 

plant <iN-erru pumped 
loop etcoNDAriY coolant 



Figure 31. Alternative refrigeration approaches (25) . 



46 



Control of the freezing process is done by monitoring ground 
temperatures at critical locations. It is necessary that the ground 
be kept at preselected temperatures, since all properties of frozen 
soil are strongly temperature-dependent. Flowing groundwater can also 
be a problem, so freezing under such conditions requires greater care 
and higher costs. 

The cost for freezing ranges from approximately $8.00 to $20.00 
per square foot of frozen wall; a weekly charge is also made for the 
time it remains frozen. If the construction time exceeds six months, 
this approach will probably not be competitive with other methods. 

At this time, the general physics related to ground freezing is 
reasonably well understood, and approximate analytic methods are 
available for necessary design calculations in the references cited by 
Sanger and Shuster. 



47 



4, SITE INVESTIGATION AND SOILS TESTING 



The site investigation for a grouting operation should be as 
thorough as necessary to furnish a basis for determining groutability 
and selecting the type of grout material applicable. Information on 
soil structure, permeability and groundwater conditions is very 
important. 

This investigation should have top priority, because this phase 
yields the information on which the grouting plans are based. Yet, the 
available literature reveals that this is a neglected area in planning 
for a grouting job or other underground construction. 

According to Peck, Hendron and Mohraz (26) . . . "One of the out- 
standing shortcomings in the state-of-the-art of soft ground tunneling 
at the present time is the manner in which subsurface information is 
obtained, presented, made available to bidders and related to the con- 
tract documents. The engineer or owner, fearing claims, is strongly 
tempted to place no conclusions regarding the behavior of the soil 
in the contract documents, although he and his advisors are probably 
the only ones having the time and facilities to make an adequate 
assessment of the subsurface conditions. The bidders, on the other 
hand, are tempted to be optimistic to enhance their likelihood of being 
the lowest bidder, and to look for every apparent deviation, significant 
or otherwise, from the conditions they say they have assumed on the 
basis of the contract documents. This mutually antagonistic relation- 
ship is unhappily growing worse and threatens to over shadow many of 
the technical improvements that potentially decrease the cost of 
tunneling." This quotation is equally applicable to the grouting aspect 
of the tunneling program. Frequently, grouting is required because of 
unforseen problems encountered in the tunnel construction. If the site 
investigation for the tunnel had been conducted in a thorough manner, 
problem soil conditions could have been anticipated and the contractor 
could have planned remedial measures. If grouting was necessary, 
time and expense would be saved in beginning the remedial grouting 
operation. 

A recent study for the Federal Highway Administration on subsurface 
investigation (27) points out that tunnel designers want to know the 
ground type, the structural defects, the physical and engineering 
properties, and the groundwater conditions. This information is also 
necessary for the design engineer should grouting be considered as 
part of the initial design planning. 

The above study also considers the feasibility of using acoustic 
methods to explore a site from long horizontal holes drilled through 
the entire site area. If additional research now in progress to further 
develop this technique is successful, this method would be very valuable 
in more accurately determining the soil conditions throughout a given 
area. 

48 



There are three fields of interest when conducting a site investi 
gation where grouting might be involved in the proposed construction. 
These are: drilling and sampling, soil properties affecting grouting, 
including laboratory and field testing, and geographical and geological 
data. 



A. Drilling and Sampling 

Drilling of boreholes and recovery of soil samples are the most 
common parts of a site investigation. Often the investigation consists 
only of a few boreholes across the site. The holes are generally spaced 
too far apart. Then it is assumed that the strata between the holes 
are consistent. This is especially not true in alluvial deposits where 
pockets and lenses of sand and clay are commonplace. In such instances, 
the assumptions are incorrect and gaps have been left in the investi- 
gation information. 

Unlike site investigations for highways, where the soil is generally 
cohesive and samples are from shallow depths, site investigation for 
construction or grouting of tunnels requires deep samples, often from 
cohesionless soils. It is virtually impossible to recover a sample of 
undisturbed cohesionless soil without using very sophisticated samplers; 
therefore, samples of soil which are recovered must be recompacted in 
the test apparatus for laboratory testing. 

A Swedish piston sampler, using metal foil which unrolls and enclosed 
the sample, has been successfully employed in Europe to obtain samples 
in soft soil up to 60 feet (18.3m) in length (28). The Delft (Holland) 
Soil Mechanics Laboratory (29) developed a continuous sampler, which 
encloses a 66mm sample in a waterproof nylon stocking up to 20 meters 
(66 ft.) in length. This sampler has been used successfully in sampling 
interbedded layers of peat, clay and sand without disturbance. Sampling 
can begin at any depth. For deeper tunneling, only that depth which is 
of interest can be sampled. Neither of these two samplers have been 
used to any great extent in the United States. 

Even under conditions where the sample is disturbed and then 
recompacted for determination of permeability, simple laboratory testing 
should be done to determine the feasibility of grouting prior to con- 
ducting the more costly field tests. 

B. Soil Properties Affecting Grouting 

When grouting is considered as a solution to a problem in cohesion- 
less soils, it is necessary to know certain properties of the soils in 
order to answer the following questions: 



49 



1. Is the soil groutable? 

2. If groutable, what type of 
grout can be used? 

3. What success can be anticipated 
if grouted? 

The soil properties that must be determined in any site investigation 
are: 

1. Permeability 

2. Porosity 

3. Particle-size distribution 

4. Pore-size distribution 

5. Chemical properties 

1. Permeability 

Permeability is that property of a soil which allows the flow of a 
fluid through it. This consideration is important since the grout fluid 
must flow into the voids of the soil to replace air or water. The 
permeability of the soil also indicates the groutability and the general 
type of grout that might be used for any particular soil, especially in 
terms of viscosity requirements. The permeability may be estimated 
from the gradation of the soil or determined by laboratory tests on 
samples of undisturbed soil or recompacted soil to approximate in situ 
conditions, or from in situ tests at the site. 

a. Permeameter Tests for Permeability : 

Computations of permeability are based on Darcy's law, which states 
that in laminar flow the velocity of perculation is directly proportional 
to the hydraulic gradient (or the ratio of the drop of head to the length 
of the soil layer). In other words, the quantity of water flowing through 
a given cross-sectional area of soil is equal to the hydraulic gradient 
multiplied by a constant called the coefficient of permeability. 
Equation 14 (given in Chapter 2) is expressed as: 

Q = Aki 

where Q = volume of flow per unit time, 

cfd or cc/min 
A = cross-sectional area of flowing 

water, sq ft or sq cm 
k = coefficient of permeability 
i = hydraulic gradient 

The cross-sectional area A is the area of the soil including both 
solids and void spaces. Since the water actually flows only through 
the void spaces, the velocity ki in equation 14 is a factitious velocity 
at which the water would have to flow through the whole area A in order 
to give the quantity of water Q which actually passes through the soil. 

50 



The coefficient of permeability k has the dimensions of a velocity, i.e., 
distance divided by time. Normally this is expressed in cm/sec. 

For the most part, permeability tests and evaluations relate the 
permeability of soil to water, or sometimes to air. For fluids other 
than water, the permeability coefficient k for water must be multiplied 
by the ratio of viscosity of water to that of the fluid. This is 
expressed in equation 15 (Chapter 2) as: 

k =^ 

g yg 

The coefficient of permeability can be determined by either a con- 
stant-head or falling-head permeability test. The constant head test 
can be performed in accordance with ASTM D 2434-68, Standard Method of 
Test for Permeability of Granular Soils (Constant Head). The quantity 
of water flowing through the soil specimen is measured for a given time 
while the head is kept constant. This test is used principally for 
coarse-grained soils with k values greater than 10" 4 cm/sec and is limited 
to disturbed granular soils containing not more than 10% soil passing the 
200 sieve. 

The falling head test is useful for fine-grained soils (fine sands 
to fat clays) with k values less than 10 _lt cm/sec. There is no ASTM test 
established, but it is conducted in the same manner as the constant head 
test, except that the head of water is not maintained constant but is 
permitted to fall within the upper part of the specimen container or in 
a standpipe directly connected to the sample (30). An illustration of 
this test principle is shown in Figure 32. 



Standpipe area a 



dh in dl 




Porous stone 



Figure 32. Falling head permeameter (32) 



51 



In the conduct of the test, water passing through the soil sample 
causes water in the standpipe to drop from h c to h x , in a measured period 
of time, t. The head on the sample at any time t between the start and 
finish is h; and, in any increment of time dt, there is a decrease in head 
equal to dh. From these facts, the following relationships may be written: 







k*A = 


a dt 


Then 




k£ / dt = -a 


from which 








k 


ad 
At x 


_ 



(17) 



where 



a = standpipe area, sq cm 

d = length of sample, cm 

A = area of sample, sq cm 

t x = time for drop in head, sec 

h = initial head, cm 

h x = final head after time t, cm 

The weak point in laboratory determination of permeability is the 
difficulty of ensuring that the amount of compaction and the structure of 
the soil sample in the permeameter is representative of that to be grouted 
in the ground. These samples, when recompacted for laboratory tests, will 
also approximate the conditions of the sediments in place. It is almost 
impossible to recover samples without altering the state of stress, the 
structure, the density and the moisture, as well as losing some of the 
finer material . 

Therefore, the laboratory samples will usually produce different flow 
rates and permeabilities than the same tests conducted in situ. It is 
good practice, however, to collect these samples and perform laboratory 
tests to obtain an indication of the permeability before going to the 
additional expense of in situ testing. If the laboratory tests give a 
permeability of less than 10" 5 cm/sec, the groutability of the soil is 
questionable. 

b. In Situ Tests for Permeability 

Permeability obtained by in situ testing provides a value which is 
based on a more nearly unaltered soil structure. This test can determine 

52 



groutability, help establish the type of grouting material to be used, 
and find the injection rates to aid in establishing a set time for the 
grout. 

Current practice of grouting companies in the United States does not 
usually include in situ permeability measurements. Perhaps this is be- 
cause most site investigations are made by soil engineering companies during 
the feasibility study, and sufficient money is not included in a grouting 
subcontract to perform the in situ testing. However, the site investi- 
gations in Europe are often performed by the same company that will do 
the grouting; so they have more freedom to conduct the site investigation 
as they desire. This arrangement enables the company to get the specific 
information needed for both designing and conducting the grouting. 

Either constant-head or falling-head field permeability tests can be 
performed in boreholes. The constant head tests may be conducted either 
with open end casing or with a packer. In these tests, water is pumped 
at a constant pressure into a hole drilled into the stratum to be investi- 
gated. With open-end casing, tests are conducted with casing set in the 
hole down to the test stratum. Pump rates and fluid volume are measured 
for a given time and the permeability calculated from the data obtained. 
In the packer test, data can be obtained in a similar manner on each 
stratum as the hole is drilled by inserting an air inflatable packer, 
since the hole will probably not stand open without casing for later tests. 
These tests are detailed in the Appendix of Volume 2, Design and Operation 
Manual, FHWA-RD-76-27. 

For constant head, open-end tests, the coefficient of permeability 
can be calculated by equation 18, which is based on electrical analogy 
experiments (64): 



where 



k = 



5.5r H 



(18) 



k = 
Q = 
r = 
H = 



coefficient of permeability 
volume of flow per unit of time 
internal radius of the casing 
differential head causing flow, 
that is, the difference in head 
between water inside and outside 
the well casing. 

This equation assumes radial flow, and may be applied where the formation 
thickness is 10D o or more, using any consistent units. When packers are 
used, the equations are: 

Q 
k = Trrrrr 1 n£=- , for L^5D (19a) 



2ttLH 



2L 

Do 



2^jT sinh Jj , for 5D >L=^D 



(19b) 



53 



where 

L = length of hole tested 
D = diameter of the hole (other symbols 
are as above) 
Jn = natural logarithm 
sinh" 1 = arc hyperbolic sine 

Example A : An NX (3-3/16" I.D.) casing is open at the end at 20 feet 
depth. The groundwater table is at 5 feet depth. Upon application of 
10 psi pressure at the ground surface, Q - 10 gal/min. Find k. 

Solution : 

u - v + in lb x iiliil 2 y 1 ft 3 
H - 5 + 10 lp x- TTF x 624 1b 

= 5' + 23.1 = 28.1 ft of head. 

From equation 18: 

l _ 10 gal/min v 12 in v 1 ft 3 

"' 5.5(1.594 in) (28.1 ft) x 1 ft x 7.48 gal 

= 0.065 ft/mi n 

= 0.033 cm/sec 

Example B : An 8' length of NW borehole (3-5/8" in diameter) is isolated 
by packers and tested with H = 10 ft., Q = 50 gal/min. Find k. 

Solution : Since L > 5D , equation 19a applies. 

v = 50 gal/min , 240 in v 1 ft 3 
2tt(8 ft) (10 ft) m 3.62 in x 7.48 gal 

=3.57 ft/mi n 

=1.81 cm/sec 

The falling head test employs a piezometer installed in a borehole 
for the purpose of measuring the rate of the falling water level against 
time. This method is an economical one which can be used in a wide 
range of soil types. A piezometer also serves the additional function 
of measuring the excess hydrostatic pressures during the field 
operations (69). 

The relation for a falling-head open-end piezometer is: 



54 



k ° nDl(t,-U 1n fc < 20 > 

where d = diameter of the standpipe 
Do^ diameter of the intake hole 
t x and t 2 = times for respective heads Hxand H 2 

Example : An AX casing (I.D. = 2.0 in) is left open-ended at 30 feet depth, 
and the water table equilibrates at 25 feet depth. The casing then is 
filled with water, and the water level drops 12 feet in 2 hours. Find k. 

Solution : In this case D = d = 2.0 inches 

H x = 25 ft; H 2 = 25-12 = 13 feet 

. _ tt(2 in) 2 1n 25 ft 
K 11(2 in)(2 hours) In 13 ft 

= 0.187 in/hour 

= 0.0079 cm/mi n or 1.316 x 10" ** cm/sec 

2. Porosity : 

The relative amount of void matter in a soil may be expressed con- 
veniently by means of either the void ratio or porosity. The void ratio 
is the ratio of the volume of voids to the volume of solids. The porosity 
is the ratio of the volume of voids to the total volume of the soil. 
Porosity is usually expressed as a percentage rather than as an abstract 
ratio. In either case, the ratio refers to the total amount of void 
space, without regard to the amount of moisture or air contained in the 
voids or pores. 



These relationships may be expressed by simple formulas as follows 

V 
V 



the void ratio, e = \ y- (21) 



s 



where V = volume of void space and 

V^= volume of solid particles and 



the porosity, V 
(in percent) n = y— x 100 

where V = total volume of soil (22) 



The volume of voids and volume of solids of a soil are determined 
from the bulk dry unit weight y^ and the specific gravity G of the soil 
mineral grains. In the case of saturated soils, the volume of voids and 
solids can be determined from the saturated unit weight y and the water 

55 



content in pounds per cubic foot W , both being readily determined by 
nuclear moisture-density gages. 



(23) 

Y w = unit weight of water (1 gm/cm 3 ,62.4 lb/ft 3 ) 

(24) 



(25) 



For dry soil : 








v s = 


Yd 

Gy w 


where 


Yw " 


unit we 




V e = 


i-v s 


For saturated soil : 








W w 




V 






T w 


where y , is as above 
'w 








V 


= i-v e 



(26) 

In the first method the specific gravity G can be measured, or may be 
assumed to be 2.65 for ordinary sands or 2.70 for clays. 

The porosity is helpful in determining the amount of grout fluid 
which would be required to completely fill the void space in the mass 
of soil to be grouted. Laboratory tests can be made for porosity, but 
the value obtained must be considered an approximation since the soil 
structure has been altered or destroyed in the sample. Tests conducted 
by Beard and Weyl (31) in 1972 indicated that the porosity varied between 
dry-loose sand and wet-packed sand, and varied with the sorting. Average 
wet-packed porosity ranged from 42.5 percent for extremely well -sorted 
sand to 27.9 percent for very poorly sorted sand. 

Grouting firms generally use a porosity value of about 33% when 
planning a grouting job. Some European grouting firms, however, assume 
a figure over 50%; consequently, they inject more grout than the voids 
can hold, resulting in the use of excessive grout and possible ground 
heave. 

3. Particle Size Distribution 

Mechanical analysis of a soil sample is the process of separating a 
soil into particle size groups, including both the sieve analysis of the 
coarser grains and the measurement of settling velocity of the fine 
grains. This analysis can be expressed as the percentage of total weight 
of dry soil particles which falls in each size class, namely, gravel, sand, 
silt-size, clay-size and collodial-size. 

56 



Another method 
percentage of total 
each of a series of 
the maximum size of 
illustration of the 
accordance with ASTM 



of expressing the grading of the soil is to give the 
weight of dry soil particles, which is finer than 
stated diameters from the smallest size up through 
particle contained in the soil. Table 3 gives an 
latter method (32). The sieve analysis is made in 
Method D 422. 



Table 


i 3 


Typical Mechanical 


Analysis of Soil (32) 


Sieve Number 


Percent Finer 


or 


or Passing 


Dia. of Grain (mm) 


by Weight 


No. 4 (4.76) 


100 


No. 10 (2.00/ 


96 


No. 20 (0.84) 


92 


No. 40 (0.42) 


89 


No. 60 (0.25) 


82 


No. 100 (0.147) 


78 


No. 200 (0.074) 


65 


(0.025) 


52 


(0.010) 


31 


(0.005) 


21 


(0.002) 


13 


(0.001) 


8 



Soil gradation may be represented by a particle size 
curve. Such a curve is plotted in Figure 33 for the soil 
Table 3 (32). 



distribution 
analysis in 



The particle-size distribution curve is an excellent way to describe 
a soil. The median grain size (D s0 ) is defined as the size where 50% of 
the soil by weight is finer and 50% is coarser. This median describes an 
average particle size, but does not delineate the range in particle sizes. 
A measure proposed many years ago by Hazen to describe filter sand is the 
effective size, D 10 , or the maximum diameter of the smallest 10%, by 
weight, of the soil particles. The uniformity coefficient (C u ) is the 
quotient obtained by dividing the maximum diameter of the smallest 60% 
by weight, of the soil particles by the effective size, or 



D 



60 

'10 
57 



(27) 





C 


ay 


size 




Silt 


size 






Fine sand Coarse sand 


Gravel 


Colloidal 












200 


T ►,. 
U.S. standard sieve No. 
100 60 40 20 10 




size 
100 

90 




4 


- 












i 


III I \, 




80 




















70 


— 


















Percent passing 

© © © 












/\ 

1 


1 
1 
1 


' 




30 
20 


- 










1 
jl 


! 
1 

1 






10 




/E 


. S., 


D„ 




1 
1 


Id,. 















i i 


i ii ii 


.1 . 


1 Ii i i I I I 


i i i i i i ii i i 


i i i i i ii 



0.001 



0.01 



0.1 

Particle size (mm) 



10 



Figure 33. Particle-size distribution curve (32) 



In Figure 33, the uniformity coefficient would be 

0.049 



C u = 



0.0012 



= 41 



A low uniformity coefficient indicates a soil in which the grains 
are fairly uniform in size. A high value indicates that the size of 
grains is distributed over a wide range. For example, a wind-blown silt 
deposit may have a uniformity coefficient of around 10 to 20, while a 
well -graded sand may range as high as 200-300. 

A low value of effective size (D 10 ) indicates that the soil contains 
a relatively large amount of fine material. A higher value indicates a 
smaller percentage of fines. 

A "rule of thumb" which has been applied to chemical grouting is 
that if the grain size is such that more than 20% passes the 200 sieve, 
the chance of successfully permeating the soil with any grout is 
negligible (33). 

Figure 34 shows the relationship between the effective size, Di , of 
the soil sample to permeability coefficient and types of soil. 

58 






1 






10" 

1 






io- J 

1 




io-' 

i 


PERMEABILITY, K 
IO" 4 

1 


IO"' 

1 




I0"« 

1 




10' 

1 


' ^ec 




1 
2 




1 
1 


1 
.6 






1 
.2 




1 1 1 
.1 .06 .02 

EFFECTIVE GRAIN DIAMETER, d 


1 

.01 

10 


1 

.006 




1 
002 




i 1 

SO 1 vrtYn 


Grcvsl 


| 


CI. 


Sond 


1 


Md 


Sond 


1 


Fi 


Sond 


Cs. Silt Md 


Sill 


1 


FI. Silt 


| 




Cloy 



Clton Grovils 



V«fy Fint Sonds 



Clton Sandt 



Coon* Fint 
Sond-provel Misturts, Till 



Silts, oraonic ft inorgonic 



" t rTo7 



Vofv»d Cloys, «tc. 



Sond- Silt- Cloy Mlsturts, Till 



Cohttlonltss tictpt for Ctmtntotlon 



Vorloble Cohesion 



Cohttlvo 



Escsssiv* wottr 

yislds, "Ids 

ipoclng 



Lorg« dio. wjlls, 
wldt spocing 



Educolor wtllt, 
norrow spocing 



Vacuum systems, 

low yislds 
norrow spocing 



Vacuum plus 
fltctroosmotis 



Loo of comprtsttd oir / 



EUctroosmotls, •Itctrochtmicol itoMlizotion 



POSSIBLE DEWATERING METHOOS 



Sondcsmtni 
Ctm«nt - 



Fraailng possible throughout 
Colloidal Grouts — — -— — Polymsrs, Resins 

Bituminous Grout! AM- 9 



Grouting In fissures only; 
grouting usually not required 



Bentonite ' 



Chromt-Llgnin 



Suspensions 



Silicons, Joosten 
Colloidal 



Solutions 



Figure 34. Correlation of effective diameter and permeability (54) . 

There is also a relationship between the particle size of the soil 
to be grouted and the particle size of particulate type grouts. The 
effects of this relationship on groutability will be discussed further 
in Chapter 5, Grout Material Selection. 

4. Pore Size Distribution 

A more direct measure of soil groutability might be its total porosity 
plus the pore size distribution. Equipment has become available recently 
to measure the distribution of pore sizes in a soil with speed and pre- 
cision; however, correlations to groutability have not yet been attempted. 
Nevertheless, useful relationships should exist, and a better knowledge 
of actual pore sizes would lead to a more intelligent selection of grout 
and grouting technique. 



59 



a. Mercury Injection Method 

Current pore size measurement techniques utilize mercury as a 
penetrating liquid because it is nonwetting and external pressure is 
needed to force it into soil pores. The amount forced usually is deter- 
mined volumetrically. 

The relation between required pressure for injection and the pore 
size is the simple capillary rise (or depression) shown graphically 
below and in equation 28. 



2r 



EMPTY PORE 



Hg 



\rS 



mi 




Tfr 2 p 



The force opposing injection into a circular cross-section capillary is 
the circumference times the liquid surface tension T times the cosine of 
the wetting angle 6. For injection to occur, this must be equalled by 
external applied pressure P times the capillary cross-sectional area: 



or 



-2 7T r T cos 9 = 77 r 2 P 
2 T cos 



r = 



(28) 



T 



where r is the capillary radius. The negative sign is needed because 
cos G is negative when 6 > 90°. Measurements of 6 for mercury against 
a variety of materials gives a range of about 112-142°; a value of 130° 
is commonly used in the calculation. T has been determined as 474 
dyne/cm at 25°C. 



Substitution, gives: 



r = 



609 



(28a) 



where r is the capillary radius in centimeters and P is the applied 

60 



pressure in dynes/cm 2 . Converting to pore diameter, 
(urn) with pressure expressed in psia: 



d, in micrometers, 



d = 



176.8 



(28b) 



The minimum pressure which may be read is about 0.5 to 1 psi, giving a 
maximum measurable pore diameter of about 350 ym, or 0.35mm. Porosimeters 
are available with maximum pressure ratings of 1000 to 50,000 psi, giving 
respective minimum pore diameters of 0.18 to 0.0035ym, the lower pressure 
instruments being least expensive. Only 177 psi is required to carry a 
determination down to 1 micron diameter pores. 

The testing method involves vacuum evacuation to obtain initially 
clear voids, then equilibration at any desired pressure or pressures. A 
complete pore size distribution requires about 4 hours, which is less 
than the time required for a conventional particle-size analysis. However, 
only one sample can be tested at a time. 

Representative pore-size distribution curves are shown in Figure 35 
for a loess (silt) soil compacted to several void ratios (34). (The 
natural void ratio was e = 0.975). Modal (or most common) diameters are 
indicated by steepest portions in the pore size distribution curves. 
These curves vary from lOym for the least dense to 3ym for the most dense 
degree of compaction, illustrating the variability in pore size distri- 
butions even with a constant particle-size distribution. 

E 
en 
\ 
o 
o 

Q 
UJ 
Q 

DC 

I- 
Z 

CO 

g 

o 

> 

o 

UJ 

_i 

o 

> 




0.1 



0.5 



1.0 



10 



50 



100 



PORE DIAMETER, MICRONS 
Figure 35. Pore-size distribution curves for a loess soil (34) 



61 



b. Errors in Assumptions 

The first unrealistic assumption for the derivation of equation 28 
is that soil pores are not actually circular. Departures from a circle 
increase the wetting surface and resistance to penetration, and decrease 
the pressurized area. A more general expression for equation 28 is: 

A T cos 6 (29) 

C P 

where A is the cross-sectional area and C is the circumference of the 
capillary. A few examples of calculated A/C ratios are given in Table 4. 
It can be noticed that the error from this assumption appears to be 
relatively unimportant if the pore radius is defined as a minimum radius. 



Table 4 
Examples of Calculated A/C Ratios 



Figure 




a 
A/C 


Minimum Radius 


a/b 


Circle 




Til 


r 


0.5 


Square 




d/4 


d/2 


0.5 


Equil. Tri 


angle 


bVT" 
12 


bV3~ 
6 


0.5 



Secondly, soil pores are not uniform in diameter throughout the soil, 
so many of the smaller pores are inaccessible at a prescribed calculated 
pressure. This has been termed the "ink bottle" effect. When pressure 
is raised, the pores may be filled, biasing the determined pore data to 
finer sizes; or, the pores may remain inaccessible, reducing the determined 
total pore volume. This type of error is fundamental to any injection 
method since the liquid (mercury) of necessity must not wet the soil, whereas 
many grouts do. 

In a static or nearly static situation a wetting fluid will be drawn 
into empty soil pores, filling the "ink bottles" from the bottom; thus 
mercury injection could underestimate grout "take" for low viscosity 
chemical grouts. On the other hand, pores filled with water already are 
wetted with a very low wetting angle, and many grouts probably will not 
displace water by surface tension (i.e., surface free energy) effects. 
Thus the "ink bottles" probably exist for grout as well as for mercury, 

62 



and the error may be small. The importance of this error has not been 
evaluated. The "ink bottles" may be investigated by depressuring and 
measuring mercury ejection. 

c. Analysis of Groutability Related to Soil Pore Size and 
Grout Particle Size 

One problem not yet resolved is the maximum allowable grout particle 
size for a particular pore size distribution, since penetration is not 
through a single opening, but through a long series of alternate widening 
and narrowing pores radiating outward into soil. Even if the minimum 
opening is twice the largest grout particle size, there is a liklihood 
that somewhere along the crooked trail two particles will arrive at a con- 
striction simultaneously, blocking the passage against further entry of 
grout. This probability of blockage is probably an inverse function of 
the grout penetration distance as 1/r -- that is, grout extending twice 
as far into soil will encounter twice the number of restrictions and 
have only one-half the chance of getting through. On the other hand, 
radial outward penetration also increases the number of routes available, 
probably as a function of the sphere surface area or r 2 , which will be 
much faster than the opposing factor 1/r. Thus, soon after pumping begins, 
the soil either should accept a particle grout or it should not. 

For rock fissures a maximum particle-to-crack width of 3 has been 
found realistic. This appears reasonable, based on a greatly diminished 
probability that four particles will arrive simultaneously in such a way 
as to bridge the opening strongly enough to resist dislodgement. An 
analogy may be drawn to rush-hour traffic in a city, and the probability 
of stoppage is greatest where traffic is heaviest, and diminishes greatly 
as alternate routes become available and traffic becomes diluted. 

A "rule-of-thumb" for grouting with particulate grouts states that 
the soil pore should be three times the grout particle diameter. This 
will allow for grout flow in the pore with little liklihood of bridging 
occurring. However, a more exact theory based on probabilities may be 
developed by assuming the number of constrictions per unit length is a 
function of soil particle size. Then probability of penetration, P, 
becomes a function of the following: 

P = f 1 , r 2 , D/d, d, C 

where r = grout penetration distance, cm 

D = pore diameter, cm 

d = particle diameter, cm 

C = grout concentration, cu cm 
and 1/r and d relate to number of constrictions in the grout path, r 2 
relates to number of paths avail abke, and D/d and C relate to probability 
of blocking at a particular constriction. These terms should be rearranged 
to give dimension! ess ratios for investigation in the laboratory. Other 
variables, such as pumping pressure and zeta potential of grout and of 
soil, may be pertinent and should be included in such a study. 

63 



d. Grouting Pressure and Seepage Forces 



A question arises whether soil structure may be lost and pores re- 
duced by grouting pressure, or more specifically by the grouting pressure 
gradient, since a large decrease in pressure over a short distance in 
effect transfers the residual pumping force to a small volume of soil. 
For example, pore clogging and a loss of permeability will increase the 
pressure gradient in the clogging soil until the pressure transfer may be 
large enough to collapse the structure of the soil and make it virtually 
impermeable. A similar effect exists with nonparticulate grout, except 
in this case, the force applied to the soil is seepage force caused by 
friction of the grout flowing through the soil pores. The effects of 
such transfer of grouting pressure to the soil is discussed further in 
Chapter 7 of this report. 






C. Geographical and Geological Data 

There are many sources of information 
particularly in built-up urban areas (35). 
available for questioning regarding the si 
offices sometimes yield valuable informati 
of the site from past years. Contour maps 
as Soil Conservation, may prove helpful, 
obtained from local or state offices to gi 
The importance of this phase was shown by 
job while sheet piling was used. Some of 
desired depth as can be noted in Figure 36 



for site investigations, 
Residents of the area are 
te. Files from city or county 
on, such as photographs or maps 

from government offices, such 
Geological maps should be 
ve the soil layers in detail, 
an occurrence in a cut-and-cover 
the piling would not drive to 




^wSt>fi£ma 



| 



Figure 36. Sheet piling on obstruction missed in site investigation. 



64 



Subsequent investigation of city files revealed that foundations of 
earlier buildings were still in place some distance below the surface, 
and these were the objects stopping the sheet piling. The boreholes used 
in the site investigation had missed these footings; however, a study of 
city maps initially would have revealed the footings before a decision 
was made to use the sheet piling. 

This phase will also show whether grouting can be done from the 
surface or whether other approaches must be used. Locations of buried 
utilities will have a bearing on this decision, since a pattern of in- 
jection pipes from the surface would probably damage the utilities. 



65 



5. GROUT MATERIAL SELECTION 



A. General Considerations 

Einstein and Schnitter (_7) have summarized the steps recommended 
for the selection of a grout for a particular operation. These steps 
are: 

(1) Soil investigation to include permeability, 
particle size distribution, flow characteristics 
of groundwater and any other limiting conditions 
for grouting. 

(2) Choice of a group of grouts which seem applicable. 

(3) Determination of grout properties using laboratory 
tests if needed. 

(4) Conducting laboratory tests to examine the properties 
of grout interacting with the soil, such as inject- 
ability, permeability reduction and unconfined 
compressive strength. 

(5) Field tests of one or more grouts to determine in 
situ injectability, set time in ground, permeability 
reduction and any unexpected conditions. 

The first step has been considered in the preceeding chapter. The 
remaining steps will be discussed in this chapter. 

B. Choice of Applicable Grout Groups 

The two main types of grouts are: 

(1) Particulate or non-Newtonian grouts containing 
particles in suspension, such as cement or clay. 

(2) True solution or Newtonian fluids, such as some 
chemical grouts. 

A Newtonian fluid is defined as a fluid whic'i, in laminar flow, 
exhibits a pressure drop directly proportional to flow rate. Laminar 
flow occurs at low flow rates and is characterized as being smooth or 
streamlined in nature. When pressure drop is directly proportional to 
flow rate, doubling the flow rate will double the pressure drop. Water, 
refined oils, sugar solutions and organic solvents are examples of 
Newtonian fluids. These have definite measurable viscosities. 

A non-Newtonian fluid is one which, in laminar flow, exhibits a 

66 



pressure drop that is not directly proportional to flow rate. That is, 
doubling the flow rate does not double the pressure drop. Pressure drop 
can be larger or smaller than the proportionate value. True viscosity 
of these fluids is not measurable. 

Some grouting contractors use a combination of particulate (non- 
Newtonian) grouts and chemical grouts in order to reduce the overall 
costs of the grout. Either a cement or cement/bentonite grout could be 
used first to fill large voids or pore space, and then the low visco- 
sity, more expensive chemical grout would be injected to fill the re- 
maining voids. Other grouting specialists use cement only if the 
permeability is 10" 1 cm/ sec or greater. 

Chemical grouts that are in common usage are based on sodium sili- 
cate, acrylamide, polyphenol ic and urea-formaldehyde, lignins and resins. 
The silicate base grouts are the most widely used. They are composed 
of water diluted solution with varying percentages of sodium silicate 
mixed with a reagent to produce a gel. Increasing the percentage of 
silicate increases the strength obtained in the soil, but also in- 
creases the viscosity of the grout. 

Sodium silicate is alkaline, so an acidic reactant is used to form 
collodial silica which aggregates to form a gel. Acid-forming materials, 
which have been used either on jobs or experimentally, include chlorine, 
ammonium salts, bisulfates, bicarbonates, sulfur dioxide and sodium 
silicofluoride. Reaction also occurs with salts of some metals, such 
as calcium, magnesium, aluminum, zinc, lead, titanium and copper. Many 
grouting companies have developed the reactant which they use with 
silicate to form their grout; therefore, most silicate grout are pro- 
prietary, and the grout composition is secret. 

Acrylic based grouts are water solutions of two organic chemicals 
and a reactant that produce a stiff gel when set. Cost is relatively 
high, but viscosity is almost as low as water, so it can be used in 
soils with wery low permeability. The material is toxic to the skin, 
and safety precautions need to be observed in handling the material 
both dry and mixed. It should not be used if the grout or the grouted 
soil will contact a fresh water supply. 

Polyphenol ic formaldehyde based grouts are liquids of low visco- 
sity which set to give high strengths. Cost is moderate. The mate- 
rial cannot be used safely in closed areas because of toxic fumes 
emitted. 

Lignin based grouts are composed of water-base lignin liquor with 
an acid reagent that produces a medium strength comparable to acryla- 
mides. The cost is low and viscosity is around 8 to 10 centi poises. 
Materials are sometimes hard to obtain and handle, except in powder 
form which is available in Europe. 



67 



fe^Ms, 



The cost is a definite factor to apply to selection of grout. 
The cost of various grouts in relation to the cost of portland 
cement grout is given in Table 5. The actual cost of a grout de- 
livered to the job site should be used for comparative purposes 
if at all possible. 



TABLE 5 
Cost Comparisons of Grout 

Type of Grout Basic Cost Figure 

Portland Cement 1 .0 

Silicate Base - 15% 1.3 

Lignin Base 1 .65 

Silicate Base - 30% 2.2 

Silicate Base - 40% 2.9 

Urea-formaldehyde Resin 6.0 

Acryl amide (AM-9) 7.0 



The in-place cost for soil grouted with cement grout is approxi- 
mately $13.50 to $35.00 Der cubic yard of soil grouted. The cost per 
cubic yard using chemical grout is from $40.00 to $190.00. The cost 
in Europe ranges from $150.00 to $200.00 per cubic meter with 
chemical grout. 

The known grouts are listed in Table 6. This information is 
a compilation from various papers and brochures showing a comparison 
of some significant properties of the grouts. This table may be 
helpful as a guide in tentatively selecting the type of grout or 
a general grout group, or for selecting a grouting company who might 
use their proprietary grout materials to perform the grouting job. 
Some grouting companies also sell their grouts to construction com- 
panies who wish to perform their own work under the direction of a 
grouting specialist furnished by the grouting company. 



68 



Table 6. Properties of currently used grouts. 



GROUT MATERIAL 


CATALYST 
MATERIAL 


UNCONFINED COMPRESSIVE 
STRENGTH (PSI) OF 
GROUTED SOIL 


VISCOSITY 
(CENTIPOISE) 


SETTING TIME 
MINUTES 


TOXICANT* 


POLLUTANT" 


SILICATE BASE 








LOW CONCENTRATION 


BICARBONATE 




10-50 


1.5 


0.1 - 300 


NO 


NO 


LOW CONCENTRATION 


HALLIBURTON CO. 
MATERIAL 




10-50 


1.5 


5 - 300 


NO 


NO 


LOW TO HIGH 
CONCENTRATION 


SI ROC - DIAMOND 
SHAMROCK CHEMICAL 


CO. 


10-500 


4-40 


5 - 300 


NO 


NO 


LOW TO HIGH 
CONCENTRATION 


CHLORIDE - JOOSTEN 
PROCESS 




10-1000 


30-50 





NO 


NO 


LOW TO HIGH 
CONCENTRATION 


ETHYL ACETATE 

SOLETANCHE & HALLIBURTON 


10-500 


4-40 


5 - 300 


NO 


NO 


LOW TO HIGH 
CONCENTRATION 


RHONE-PROGIL 600 




- 


- 


- 


- 


- 


LOW TO HIGH 
CONCENTRATION 


GELOC-3 

H. BAKER CO. 




10-500 


4-25 


2 - 200 


NO 


NO 


LOW TO HIGH 
CONCENTRATION 


GELOC - 3X 




10-250 


4-25 


0.5 - 120 


NO 


NO 


LIGNIN BASE 
















BLOX-ALL 
TDM 

TERRA-FIRMA 
LIGNOSOL 


HALLIBURTON CO. 

MATERIAL 
CEMENTATION CO. 

MATERIAL 
INTRUSION CO. 

MATERIAL 
LIGNOSOL CO. 

MATERIAL 




5-90 
50-500 
10-50 
10-50 


8-15 

2-4 

2-5 

50 


3 - 90 

5-120 

10-300 

10 - 1000 


YES 
YES 
YES 
YES 


YES 
YES 
YES 
YES 


ACRYLAMIDE BASE 

















AM-9 



FORMALDEHYDE BASE 
UREA-FORMALDEHYDE 
UREA-FORMALDEHYDE 

RESORCINOL FORMAL- 
DEHYDE 

TANNIN - PARA- 
FORMALDEHYDE 

GEOSEAL MQ-4 & MQ-5 



UNSATURATED FATTY 
ACID BASE 



POLYTHIXON FRD 



DMAPN and AMMONIUM 
or SODIUM PERSULFATE 



HALLIBURTON CO. 

MATERIAL 
AMERICAN CYANAMID 

MATERIAL 
CEMENTATION CO. 

MATERIAL 
BORDEN COMPANY 

MQ-8 

BORDEN COMPANY 
MATERIAL 



CEMENTATION CO. 
MATERIAL 



CO. 



50-500 

OVER 1000 
OVER 500 
OVER 500 



OVER 500 



1.2 - 1.6 



0.1 - 1000 



10-80 



25 - 360 



YES 



YES 



10 


4 - 60 


YES 


YES 


13 


1 - 60 


YES 


YES 


3.5 





YES 


YES 



NO 



Nil 



* - A material which must be handled using safety precautions and/or protective clothing. 
** - Pollutant to fresh water supplies contacted. 
*** - Also available from grouting companies under trade names of PWG or Injectite-Q. 



69 



Resin grouts of polyester or epoxy base are used in applications 
where extremely high strength is desired. One such grout is a furan 
resin, furfuryl alcohol dissolved in a nonaqueous solution, which is 
hardened by the addition of an acid. These grouts are generally high 
in viscosity, and are used in repair grouting of concrete structures 
or other similar applications. Total quantity used of this type grout 
is small. 

The ideal grouting system is a single Newtonian fluid with the 
lowest possible viscosity, a controlled setting time and an appreci- 
able gel strength of indefinite performance. Cost is a dominate 
factor, but should include not only the materials but also the mixing 
and injection. 

Dempsey and Moller (8) list twelve aspects which should be con- 
sidered in grout selection by the grouter who must meet a performance 
specifications: 

a. The reliability and completeness of the soils 
information available. 

b. The most practical method of introducing grout 
into the ground. 

c. The degree of permanence required of the grout. 

d. The possible effects on existing structures of 
ground movement as a result of grouting. 

e. The degree of saturation of the soil to be 
injected or the possibility of groundwater 
movement. 

f. The chemical composition of the groundwater 
and/or soil which might inhibit the reaction 
of the grout constituents or which might be 
aggressive to the set grout. 

g. The risk and effect of grout drying out upon 
exposure. 

h. The extent of the treatment and the spacing 
of injection points in order to produce the 
desired effect of impermeability or imparted 
strength. 

i. The toxicity of the products of the reaction 
and their possible effect on groundwater or 
underground operations. 



70 



urn amm! ...... ■ 



j. The working environment in which the grouting 
materials have to be stored, mixed and injected, 
should any of them be toxic. 

k. The justification and economics of providing 
intensive supervision for the more sophisticated 
processes. 

1. The availability of grouting materials in time 
both to begin and to sustain an operation where 
the total requirements are difficult to access. 

Figure 37 gives the limits for various types of chemical grouts 
which can be used in different soil. Selection of grout types can 
be made based on the soil properties found in the site investigation 



COARSE IILT 



»rL T INON-PL Af TIC) 




1 " c ". 



Efectio osmosis 
I Possible 



10.0 



1.0 



0.1 



0.01 



0.001 



GRAIN SIZE IN MILLIMETERS 



Figure 37. Soil limits for grout injectivity (11) 



71 



C. Grout Properties 

The grout properties of available grouts should be considered 
when selecting grouts. Since it is possible that a particulate grout 
may be used in preliminary grouting, these will be disucssed as well 
as the chemical grouts. The important properties to consider are 
viscosity characteristics, setting times, strength of grout and 
grouted soil, water tightness, stability or permanence and toxicity. 

1. Viscosity Characteristics 

In considering a particulate grout material, it is important 
that the particles of the grout material be substantially smaller 
than the pores between the soil particles. In order to penetrate a 
formation at a reasonable pressure and flow rate, the size of the 
largest suspended particles in the grout cannot be greater than 
about one-third the size of the pores. Generally, pores are about 
one-fifth as large as the grains. For soil consisting predominately 
of one grain size, grout particles should be less than one-tenth of 
the soil particle mean size. This rule does not apply to true solu- 
tion chemical grouts, where the viscosity can be measured. It would 
be applicable to particulate type grouts, such as cement or clay 
grouts. Figure 38 shows limiting grain sizes of materials that can 
be successfully grouted by particulate grouts. These data are based 
on experience and testing and should be used only as a general 
guide (Id). 

Another way of expressing the relationship between the particle 
size of the grout and the grain size of the soil to be grouted is by 
the groutability ratio, GR. 



GR = 



D 
15 



D 
85 



where 

D = the 15% size of the soil to be 
15 grouted (fifteen percent of the 
soil has finer grain sizes). 

and 

D = the 85% size of the grout particles, 
85 where 85% of the grout material is 
finer. 

Based on tests by the Corps of Engineers (36), the limits of 
groutability based on the GR value are shown in the graph on 
Figure 39. The right end of each bar represents the sand-grout 
ratio for the finest sand proven groutable while the left end 
represents the sand-grout ratio for the coarsest sand proven 
not groutable. Since tests reported were limited to two grouting 

72 




in 

CD 

> 
J- 

zs 
o 

<D 
N 

to 

I 

c 

•r- 

s- 

CT) 



•f— 

S- 
(D 

+J 
to 

E 

4-> 
O 

s- 

T3 

to 



o 

CO 



00 
oo 

0) 

s- 

CD 



o 


o 


o 


o 


o 


o 


O 


o 


o 


o 


o 


O) 


oo 


f- 


CO 


IT) 


■t 


CO 


CM 


*- 



1HDI3M AS H3NIJ iN33H3d 



73 



agents, determination of this grouting criterion is based on suc- 
cessful penetration of the permeameter specimens only. 

It can also be noted that the cement grouts tested would not 
penetrate a sand having a sand-grout particle diameter ratio less 
than 11, but that each cement grout tested would penetrate materials 
with sand-grout ratios greater than 24. Therefore, these values may 
be considered as criteria for determining groutability. However, 
the data tend to indicate that a minimum practical limiting grout 
ratio for portland cement grouts should be somewhere in the vicinity 
of 19. 



SCALPED TYPE HI 
PORTLAND CEMENT(<30U> 

COMMERCIAL TYPE IK 
PORTLAND CEMENT 



WMfflMA 



WILL NOT 



FINER SOIL 



GROUT 



WMMMMMZMA 



111=18 
85 



WILL 



GROUT COARSER 
SOIL 



10 



_L 



15 20 

D 15 (SAND) 
D 85 (GROUT) 



25 



Courtesy of Corps of Engineers 



Figure 39. Limits of groutability of sands by particulate grouts, 

74 



It is difficult to use particulate grouts for permeation 
grouting in soils finer than very coarse sand without the possibi- 
lity of either plugging the soil face or creating a fracture. This 
fact limits the use of cement grouts to soils with permeability 
greater than 10" 1 cm/sec and clay grouts to soils with permeability 
greater than 10" 2 cm/sec. 



The viscosity of the chemical grouts varies with 
of solids in solution. This is shown graphically in 
several chemical grouts and a bentonite grout (37). 
on each curve indicates the concentration primarily u 
operations. Since only the AM-9 is a true solution, 
given for the other grouts must be considered as an a 
sity because they contain minute particles in suspens 
it does give some idea of the effect on viscosity by 
concentration of a grout. 



the percentage 
Figure 40 for 
The wide band 
sed in field 
the viscosities 
pparent visco- 
ion. However, 
increasing the 



In addition, all of the grouts except AM-9 gradually increase 
in viscosity with time after mixing until gelation takes place. The 
AM-9 grout remains a constant viscosity, then increases suddenly in 
viscosity as it sets. 

Increases in temperature will reduce the viscosity only a very 
small amount, so comparisons shown in Figure 40 would not change 
appreciably by temperature variation. 



100 
80 



1 




















1 










1 










1 










1 










J 






























1 






-N"M 


/ 






-J 




1 




§11 


A 




M 




<o// 


$A 




i\ 




S/L 


^JV 




z\ 




Wl 






CO I 




w V 






\ 








^ 


4 


/yF 


H<*'1j 







10 20 30 40 50 

CONCENTRATION OR PER CENT SOLIDS 



Figure 40. Viscosities of Various Grouts (11 ) 
75 



2. Setting Time 

The setting time, sometimes called gel time or the induction 
period, is that time between the addition of the catalysts and the 
formation of a gel (38). With cement grouts, it is the time re- 
quired to harden, or thicken to a point of immobility. 

The basic cement grout is a portland cement grout, and the water 
ratio can range from less than 1:1 to as thin as 20:1. Bentonite can 
be used to provide increased volume at less cost. Percentages up to 
8 percent are common. Other chemicals can be added to accelerate the 
setting. Sand is sometimes added when filling large openings. 

Setting time, or the time to harden, is a matter of hours; this 
characteristic is generally the same as thickening time. Thickening 
time is a terminology used in oil well grouting for the time required 
for a cement slurry of a given composition to reach a consistency of 
100 units of consistency (Uc), determined by methods outlined in 
American Petroleum Institute standard RP 10B. A unit of consistency 
is a standard value of measurement relating torque equivalent to 
degrees of firmness of the cement slurry. Thickening time for a 
Portland cement grout with a 0.5:1 water-cement ratio is about 4 
hours at an ambient temperature of 80° F. Pumpability of this grout 
would be about 70% of the thickening time, or approximately 3 hours. 
As the water-cement ratio is increased, thickening time and pumpabi- 
lity will increase proportionally. 

Thickening time is measured in the laboratory by a consistometer. 
Figure 41 shows a picture of the device. A sliding wire bridge gives 
a voltage reading which is calibrated to relate to units of consistency, 




Courtesy of Halliburton Services 
Figure 41. Cement Consistometer 



76 



The setting time or gel time of most chemical grouts can be 
varied from a few minutes to an hour or longer. Some can be com- 
pounded to give only a few seconds setting time. Variations in 
the amount of catalyst or reactant added, or variations in the 
concentration of the primary constituent, affect the setting time. 
An increase in the temperature of the grout, or the use of accele- 
rators, decreases the set time. 

Setting time also depends to some degree on the process used. 
When the Joosten (two-shot) process is used, setting time is almost 
instantaneous. When a one-solution batch type is used, a setting 
time of less than 20 minutes is not recommended in order to insure 
placing the grout before setting occurs. A short setting time 
(1 to 20 mins) can best be obtained using a two-stream process. 

The choice of a setting time depends on several factors. Prime 
factors are: 

a. The volume of grout to be injected 

b. The soil permeability 

c. The porosity of the soil, and 

d. The rate of groundwater flow 

The grout should be injected at a pressure below fracturing 
pressure. The set time must be long enough to permit the required 
amount of grout to penetrate to the selected radius. This time will 
be governed by the soil permeability for the selected grout. 

When pumping into flowing groundwater, the grout should be 
injected at a rate equal to or greater than that of the flowing 
water to prevent excessive dilution or total loss of grout. Set- 
ting time should be made as short as possible so that the grout 
will set while injecting, thus forcing the grout into other chan- 
nels or pore spaces to give coverage over the desired area. It 
is difficult to use cement grouts in formations with rapidly 
flowing water, unless special accelerators are used. 

3. Strength 

The prevalent means of measuring the strength of grout is by 
unconfined compressive strength tests on mixtures of grout and 
soil. However, there is not standard procedure for this test 
with cohesionless soil, so the values given in the literature for 
different grout formulations must be recognized as approximate 
values. To be meaningful, the soil composition used for the 
tests must be the same, and the sample composition and curing 
must be uniform from one test to another. 



77 



Most grouting companies conduct their own tests on the grouts 
used, and their operations are based on this information. The soil 
used in most cases is specified as a medium fine-grain sand. Both 
angular and round grain sands are used. Some companies on the 
European continent use a medium fine-grain sand known as Fontaine- 
bleau sand for the test samples. 

Wide ranges of unconfined compressive strength values are re- 
ported in various papers referenced in this study. Values are 
given for a particular grout without reference to grout concen- 
tration or composition. For example, acrylamide grout (AM-9) is 
shown in one source at 70 psi (4.92 kgs/cm 2 ) for 10% concentration, 
and in another table, it is listed at 50 to 500 psi (3.52 to 35.2 
kgs/cm 2 ). Similar variations are obtained on other grouts also. 

These discrepancies can be obtained on the same grout by a dif- 
ference in test procedure or soil sample preparation. If the grouted 
samples to be tested are kept wet in order to be more representative, 
a much lower strength value would be obtained than a test on the 
same sample when permitted to dry before testing. In short, pub- 
lished data on strength properties are generally not suitable for 
comparison because of a lack of uniformity in test specimen pre- 
paration, soil used, curing time and environment, and method of 
testing (39). 

The lack of a standard test procedure is certainly an important 
factor in the variety of results published for the strength of 
grouted soil. In the tests described by Warner (39), the sample 
was made by pouring sand into the mixed grout and forming a test 
cube. In a discussion of this paper by Fawcett (40), the ex- 
perience of a 12-year research program is cited to show that the 
best procedure for producing a grouted sample is to inject the 
grout into a soil sample which has been compacted to a reasonable 
facimile of actual soil conditions. 

Skipp and Renner reported (41) extensive tests using three 
grout materials in closely graded coarse and medium sands. Using 
these controlled tests, with samples kept wet until the unconfined 
compressive strength was measure, values were obtained as shown in 
Table 7. Even under well controlled test conditions, a range of 
values was obtained for some grouts. These are, in general, much 
lower than reported in most of the literature; but values are prob- 
ably more representative of actual strengths. The strengths are 
consistently higher in medium sands than in coarse sands. 



78 



TABLE 7 
Tests of Grout Materials in Sand 



Coarse Sand 


Medium Sand 


Test 


Silicate 


Urea-Formaldehyde 


Polyester 


Sil icate 


Polyester Resin 


Stress 


Relative 

Density 

Range 

Per Cent 


Stress 


Relative 

Density 

Range 

Per Cent 


Stress 


Relative 

Density 

Range 

Per Cent 


Stress 


Relative 

Density 

Range 

Per Cent 


Stress 


Relative 

Density 

Range 

Per Cent 


Unconfined 
Compression 

Tensile 


130-290 
14-46 


58-97 
52-95 


7.0-27 
1.2-10.4 


41.5-67 
61.7-74 


3,260- 
3,530 


40-57 


245-280 
25-63 


50-92 
50.93 


4,075- 
4,760 


78-99 



The graph shown in Figure 42 gives a good comparison of un- 
confined compressive strengths for cement and several chemical 
grouts; these grouts were injected into a sample of medium-fine, 
wet, compacted sand and cured wet in tests reported by Diamond 
Shamrock Corporation (1_3). 



400 



3 50 



200 




125 



GROUT CODE 

A - CHROME-LICNIN I 7 Vo 

8 - CHROME-LICNIN 25% 

C - ACRYLAMIDE 10% 

D - 40% SILICATE 

E - 50% SILICATE 

F - 6 0% SILICATE 

G - CEMENT (LIME MODIFIED) 



Figure 42. Compressive strength of various grouts 



79 



vr 



This graph also shows that increased concentration of the basic 
grout component gives a similar increase of strength in the grouted 
sample. When the grout is to be used only to reduce permeability, 
the strength becomes less important and must only be sufficient to 
withstand the hydrostatic water head. 

a. Strength Theory 

A better understanding of the strength-giving properties of grout 
can be obtained by understanding the sources of strength in soil. One 
of these sources is grain-to-grain sliding friction which, in accord 
with Amonton's Laws of friction, is proportional to stress applied 
normal to the shearing plane, illustrated in Figure 43 (a). In this 
relationship the shearing strength x f relates to the normal stress 
a as 

x r = a tan d> 

f r s 

where tan <$> is the coefficient of sliding friction. 

Strength increases more rapidly with normal stress in a dense sand 
than in a loose sand. The added strength, shown in Figure 43 (b), may 
be considerable as it reflects the degree of grain interlocking which 
must be overcome before the soil can shear. The "unlocking" occurs 
by grains sliding up and over one another, causing a measurable 
dilatancy or volume expansion of the soil. The greater the 
amount of dilatancy required for soil to shear, the stronger the soil. 
Also, since expansion represents work against the normal stress a, 
the higher the normal stress the larger the dilational component of 
the shearing resistance. This means that the effect of interlocking 
is additive to that of sliding friction. An excellent analogy is 
two sheets of sandpaper placed face-to-face under pressure; in order 
to slide one over the other, they must slightly move apart, meaning 
work against the applied pressure. Since the two components of 
strength ordinarily are measured together, <$> is designated the angle 
of internal friction, to include both frictional and dilatancy com- 
ponents, and tan <j> is the coefficient of internal friction. 

The separate contributions of friction and dilatancy to shearing 
strength may be quite important for evaluating effects of grouting, 
particularly if filling of soil pores with solids means that the 
pore spaces no longer can be distorted to accommodate moving grains. 
The net effect would be a considerable increase in dilatancy and 
internal friction, even with no cementation whatsoever. Unfortu- 
nately triaxial test data are not readily available for soil samples 
before and after grouting, but it appears likely that (j> could be 
raised from about 26° for in situ, loose-sand soils to as high as 
45° to 55°, thereby doubling or tripling their strength (indicated 
by tan <j> ) at any particular normal stress with no contribution 
from cementation of the grout. 

80 



(a) 
LOOSE SAND 



SHEARING 
STRENGTH 
T f , PSI 




NORMAL STRESS (T. PSI 



(c) 
GROUTED SAND 



r« 




DILATANCY 
SLIDING FRICTION 



COHESION 



Mh 



(e) 



y y y v 




(b) 
DENSE SAND 



T 



DILATANCY" 




(d) 



UNCONFINED 

COMPRESSIVE 

STRENGTH 




Qu 



Figure 43. Soil strength characteristics. 



81 



A third contributor 
Figure 43 (c), or sheari 
Cohesion exists in clay 
ing, and represents an i 
soil grains. Cohesion a 
as portland cement or si 
tensile strength of the 
less than the indicated 
gressive failure). 



to soil strength is cohesion c, shown in 
ng strength at zero applied normal stress, 
soils as a result of consolidation or dry- 
nherited or intrinsic tension t^ between 
Iso is generated by cementing agents, such 
licate grouts, with t.j representing average 
bonds. (Measured tensile strengths will be 
ti because of stress concentrations and pro- 



The relation between cohesion c, friction angle <j>, and uncon- 
fined compressive strength q u is shown in Figure 43 (d), where the 
arc represents a Mohr circle drawn through a = and tangent to the 
failure envelope. From this it can be shown that 



q u = 2c cos <|> 
1 - sin <j> 



(30) 



The unconfined strength is particularly sensitive to cohesion c, 
since if c = 0, q u = 0, regardless of the value of <|>. However, q u 
may be increased several fold by increased <j), the explanation being 
that even in the unconfined test a component of the load is exerted 
as normal stress against the shearing plane, shown in Figure 43 (e). 

ction angles is given as 



The theoretical ratio q for 


di 


ifferent 1 


follows: — 






4>° 




Vc 







2.00 


10 




2.38 


20 




2.86 


30 




3.46 


40 




4.29 


50 




5.49 


60 




7.46 



Thus increasing <j> from 20° to 50° will increase 
pressive strength ratio from 2.86 to 5.49, even 
tion from cementation. 



the unconfined com- 
with no contribu- 



te influence of increased friction angles by grouting should 
be several times more important in the field than is indicated by 
the effect on unconfined compressive strength, because of higher 
pressure existing in soils in situ. These pressures act against 
potential shearing planes, so any increased frictional response 
along these planes will greatly increase the shearing strength. 
The amount of this increase is shown by the well-known Coulomb 
equation. 



82 



x f = c + a tan <|> (31 ) 

where x f = shearing stress at failure 

c = cohesion 

a = normal stress on the 
shearing plane 

<f> = angle of internal friction 

As an example, consider the overburden pressure at a depth of 40 feet 
(12.2 m) under soil weighing 120 pcf (1922.4 kgs/cu m), with the water 
table at the ground surface. The buoyant unit weight is then 120-62.4 
= 57.6 pcf (92.5 kgs/cu m), 62.4 being the unit weight of water. At 
40 feet (12.2 m) depth, a in the vertical direction is 40 x 57.6 = 
2304 psf (11250 kgs/sq.m). If cohesion is zero, grouting which changes 
only the friction angle <J> from 20° to 50° will increase shearing re- 
sistance on a horizontal plane from 

x f = + 2304 tan 20° = 839 psf 

to 

t = + 2304 tan 50° = 2746 psf, or 

by a factor of 3.3. Thus for design purposes, it would appear that 
c and <f) should be separably determined on the grouted soil. This 
may be done by laboratory direct shear or triaxial testing; methods 
of such determination in situ are discussed in Chapter 8. 

If grouting pressure substantially relieves soil grain-to-grain 
contact pressures, grain-to-grain sliding friction may be reduced 
and substituted by grout-to-soil sliding friction. In cohesionless 
soils with relatively high permeability, the effect of grout-to-soil 
sliding friction would be minimal. The extent of this reduction in 
sliding friction will depend on the extent of dissipation of grouting 
pressure prior to setting. If the grout sets too quickly and traps 
excess pore pressure, the grout-to-soil sliding friction may become 
a major factor to consider. 

b. Strength Tests of Grout Material 

Laboratory testing and evaluation to obtain grout strengths of 
the gel formed by the grout have been made by at least one grouting 
company. A cone-type, grease penetrometer (Precision Scientific 
Instrument Company Senior Model Universal Type), with a 200-gram 
weight for cone assembly, was used in the tests. 

Tests were conducted in accordance with ASTM Test D217-68 on 
an acrylamide grout, using grout concentrations from 4% to 10%. 

83 



The values obtained showed that this could be an approach to determine 
strengths and solids concentration of various gels. Once a standard 
is established for this test, results could possibly be related to 
compressive strength of given soils in standardized tests. Values thus 
obtained might be meaningful enough to use in specifications for grout- 
ing jobs. 

4. Water Tightness 

• 

Water tightness is the ability of the grout to prevent passage of 
water through the gelled grout. A grout must be impermeable, or 
possess almost zero penetration to be successful in water shutoff ap- 
plications or strengthening. This quality should be determined by the 
manufacturer for any grout and be a part of the specification for the 
grout, rather than having to be determined by the user of the grout. 

The grout should also not be subject to syneresis, which is the 
progressive exudation of water from a gel with time after the set of 
the gel (37). This phenomenon will change the permeability of grouted 
soil to some degree in a period of time, corresponding to the concen- 
tration of the gel. This should also be given in the manufacturer's 
grouting specifications. 

5. Stability or Permanence 

The stability of a grout during mixing is controlled in one- 
solution grouts by the use of additives to prevent premature re- 
action. In the Joosten process and the two-stream method, it is 
necessary to keep the two components separate until the reaction 
is desired. 

The stability over a long term, or the permanence of the grout 
in the soil, may be important depending on the purpose for the 
grouting. In cases where permeability reduction of water shutoff 
is desired for a limited time, permanence is not a factor. In 
strengthening applications or for permanent water stoppage, per- 
manence would be desirable. 

Silicate grout can be permanent or limited, depending on the 
distribution and the process used. In a commonly used one-shot 
formulation, the result is a nonpermanent gel which can be used as 
a temporary aid in construction (42). The other grout types are 
considered permanent. 

Some grouts, such as organic acqueous monomers, are permanent 
and stable, but tend to shrink upon drying or when not in contact 
with water. However, the gel swells back to its original volume 
upon contact with water. 



84 



6. Toxicity 

The toxicity of grout is becoming more important because of the 
emphasis today on safety and pollution. Many of the chemical grouts 
are toxic to the skin, while some have vapors which are injurious to 
the lungs. The silicate grouts are generally not toxic. Grouts 
which require special precautions for handling are generally so 
identified by the manufacturer. 

In most cases, the toxicity comes from the reactant or activator 
used with the basic component. Sodium dichromate, used as an acti- 
vator with chrome lignin grout, can cause ulcerous sores which are 
difficult to heal (42), so the use of gloves and goggles are required, 
The AM-9 basic chemical is neurotoxic by skin contact, inhalation or 
swallowing. The liquid catalyst used with AM-9 is slightly caustic 
and mildly toxic. It is necessary to wear gloves and goggles while 
working with these grouts. 

Other than silicate grouts, most chemical grouts are pollutants 
for fresh water. These grouts cannot be used when grouting on a 
dam or where a water supply might be contacted by the grout. In 
European operations, inspectors from the government check on jobs 
to insure that no pollutant grout ever comes in contact with ground- 
water. 

D. Grout Testing - Laboratory and Field 

Laboratory tests should be made on the tentatively selected 
grouts by flowing the grout through a wetted, recompacted soil sample 
until set occurs. Injectability and pressure can be observed during 
this test. After the grout sets, the sample should be kept moist 
until unconfined compressive strength tests can be made. It is pos- 
sible to make permeability measurements before and after grouting 
the sample, prior to the compressive strength test. 

If possible, field tests should be made at the grouting site by 
pumping water and then grout. Such tests will substantiate labora- 
tory tests and also indicate more accurately the pumping rates, 
pressure required, effect of flowing groundwater on grout, etc. 
These tests should determine the grout to be selected for the job. 



85 



The values obtained showed that this could be an approach to determine 
strengths and solids concentration of various gels. Once a standard 
is established for this test, results could possibly be related to 
compressive strength of given soils in standardized tests. Values thus 
obtained might be meaningful enough to use in specifications for grout- 
ing jobs. 

4. Water Tightness 

Water tightness is the ability of the grout to prevent passage of 
water through the gelled grout. A grout must be impermeable, or 
possess almost zero penetration to be successful in water shutoff ap- 
plications or strengthening. This quality should be determined by the 
manufacturer for any grout and be a part of the specification for the 
grout, rather than having to be determined by the user of the grout. 

The grout should also not be subject to syneresis, which is the 
progressive exudation of water from a gel with time after the set of 
the gel (37). This phenomenon will change the permeability of grouted 
soil to some degree in a period of time, corresponding to the concen- 
tration of the gel. This should also be given in the manufacturer's 
grouting specifications. 

5. Stability or Permanence 

The stability of a grout during mixing is controlled in one- 
solution grouts by the use of additives to prevent premature re- 
action. In the Joosten process and the two-stream method, it is 
necessary to keep the two components separate until the reaction 
is desired. 

The stability over a long term, or the permanence of the grout 
in the soil, may be important depending on the purpose for the 
grouting. In cases where permeability reduction of water shutoff 
is desired for a limited time, permanence is not a factor. In 
strengthening applications or for permanent water stoppage, per- 
manence would be desirable. 

Silicate grout can be permanent or limited, depending on the 
distribution and the process used. In a commonly used one-shot 
formulation, the result is a nonpermanent gel which can be used as 
a temporary aid in construction (42). The other grout types are 
considered permanent. 

Some grouts, such as organic acqueous monomers, are permanent 
and stable, but tend to shrink upon drying or when not in contact 
with water. However, the gel swells back to its original volume 
upon contact with water. 



84 



6. Toxicity 

The toxicity of grout is becoming more important because of the 
emphasis today on safety and pollution. Many of the chemical grouts 
are toxic to the skin, while some have vapors which are injurious to 
the lungs. The silicate grouts are generally not toxic. Grouts 
which require special precautions for handling are generally so 
identified by the manufacturer. 

In most cases, the toxicity comes from the reactant or activator 
used with the basic component. Sodium di chroma te, used as an acti- 
vator with chrome lignin grout, can cause ulcerous sores which are 
difficult to heal (42), so the use of gloves and goggles are required, 
The AM-9 basic chemical is neurotoxic by skin contact, inhalation or 
swallowing. The liquid catalyst used with AM-9 is slightly caustic 
and mildly toxic. It is necessary to wear gloves and goggles while 
working with these grouts. 

Other than silicate grouts, most chemical grouts are pollutants 
for fresh water. These grouts cannot be used when grouting on a 
dam or where a water supply might be contacted by the grout. In 
European operations, inspectors from the government check on jobs 
to insure that no pollutant grout ever comes in contact with ground- 
water. 

P. Grout Testing - Laboratory and Field 

Laboratory tests should be made on the tentatively selected 
grouts by flowing the grout through a wetted, recompacted soil sample 
until set occurs. Injectability and pressure can be observed during 
this test. After the grout sets, the sample should be kept moist 
until unconfined compressive strength tests can be made. It is pos- 
sible to make permeability measurements before and after grouting 
the sample, prior to the compressive strength test. 

If possible, field tests should be made at the grouting site by 
pumping water and then grout. Such tests will substantiate labora- 
tory tests and also indicate more accurately the pumping rates, 
pressure required, effect of flowing groundwater on grout, etc. 
These tests should determine the grout to be selected for the job. 



85 



6. GROUT EQUIPMENT 



The equipment needed to perform a grouting operation includes: 

(a) Drilling or Driving Equipment 

(b) Mixing and Proportioning Equipment 

(c) Pumping Equipment 

(d) Injection Piping 

(e) Monitoring Equipment 

This equipment is normally furnished by the grouting company. Some 
items (such as drilling equipment) are rented or leased by the smaller 
companies as it is required. Most larger grouting companies, especially 
in Europe, own their equipment, and some even build their drilling or 
pipe placement machinery, pumps and equipment. 

A. Drilling and Driving Equipment 

Driving equipment is used to drive grout pipes (lances) into the 
ground for grouting at shallow depths. The driver can be some type of 
mechanical or hand-held hammer. A modified jack hammer is sometimes used 
to drive the grout pipe into the ground. A track drill can be utilized 
also for this purpose. The power source is normally air. One United 
States company uses a hydraulic hammer of their own design which delivers 
7,000 blows per minute. 

If the grouting is to be performed as the grout pipe is withdrawn 
from the total depth, some type of pulling device must be used which will 
permit the pipe to be pulled slowly in short stages. There does not 
seem to be any equipment specifically made for this purpose, so most 
operators use "chain booms" on a hydraulic lift. This does not afford 
a smooth operation, since it causes the pipe to jump several feet as the 
pull overcomes the friction of the pipe in the ground. 

Drilling equipment includes small rotary drill rigs, track drills 
and special hydraulic drilling machines. A typical drill is shown on 
a field site in Figure 44. Much of the grouting is conducted through 
plastic pipes grouted in the drilled holes. All the grouting jobs 
visited in Europe were performed with this technique except one where 
vibration was used to sink special small elements to a desired depth. 

B. Mixing and Pumping Equipment 

1. Handling of Materials 

Cement, bentonite and powdered chemical grout materials are normally 
furnished in sacks or cartons. For large jobs, the materials are avail- 
able in bulk and are stored in large tanks at the job site. Dry materials 
are moved from the storage tanks to the mixing tank using screw conveyors. 

86 




Figure 44. Drilling machine on grout job in France, 




Figure 45. Batch plant for large grouting operation, 

87 



A batch plant with a tank for each material is shown in Figure 45. On this 
job in France, the material was mixed in tanks located in the metal build- 
ings and pumped to the injection pumps near the grout pipes in an exca- 
vation as shown in Figure 49. 

Liquid materials are stored in tanks also, and are moved with a 
proportioning pump to the holding tanks located adjacent to the injection 
pumps. Most European grouting companies now have this equipment automated 
so that proper amounts are fed to the pumps and mixing tanks by setting 
the desired amounts on a control panel. 

2. Grout Mixing and Pumping 

a. Cement Type Grout 

Cement mixing equipment, which has been used for years in mixing 
cement for grouting of dams, consists of a tank containing paddles or 
some type of mixing and stirring mechanism; these paddles may be operated 
by an air motor or other power source. Mixer sizes vary from one or two 
cubic foot capacity up to 25 or 30 cubic feet, depending on the job 
requirements. Usually the grout plant includes a holding tank where the 
cement grout slurry is agitated while waiting for use. Water-cement 
ratios are kept high initially (about 3 to 5) to prevent clogging the 
pores, then more cement is added as the injection pressure indicates the 
feasibility. 

Cement grouts (or bentonite) can be pumped satisfactorily with 
either piston-type, positive-displacement pumps or progressive cavity 
pumps. Accurate pressure gauges are required, and these should be rated 
for the pressure range expected for the job. A water meter should be 
used to permit control of the water-cement ratio. Figure 46 shows a 
skid-mounted, progressive cavity pump with a hopper to receive cement 
slurry from the mixer or holding tank. This type pump has a steel 
helical rotor turning within a flexible double-thread helical stator, as 
shown in the cutaway drawing (Figure 47). The meshing helical surfaces 
push the fluid ahead with uniform movement and low turbulence. These 
pumps also are satisfactory for pumping chemical grouts. 

b. Chemical Grouts 

Mixing tanks for the chemical grouts must be constructed of materials 
not affected by the chemicals being used for the grout. The acryl amide 
grouts must be mixed in tanks of plastic, aluminum or stainless steel. 
Since most of the chemicals go into solution readily, minimal mixing 
action is required. The tank might contain mechanical paddles driven by 
an air motir, but stirring could be done with a wooden paddle for small 
batches. For jobs using large quantities of grout, large tanks with 
some type of stirring or blending device would be required. 

Chemicals and water must be proportioned accurately. Some companies 
that supply grout components will furnish prepackaged and color-coded 
chemicals to make mixing as simple as possible. 

88 




Figure 46. Progressive cavity type grouti- 



ng pump. 




Figure 47. Cutaway view of progressi 

89 



ve cavity pump, 




Figure 50. Electronic console for grout pump automation, 




Figure 51. Grout pumps and mixing tanks in van unit, 

92 




Figure 52. Recording gauges and pump controls in grouting trailer. 



1 . Drive Points 

For work at shallow depths, where pressure must be kept to minimum 
values to prevent lifting the ground surface, injection can be made 
through small size injection tubes driven into the ground with some sort 
of hammering device. This is perhaps the most widely used method in the 
United States. Special tools are available for this type of injection. 
Figure 53 shows one such tools with a retained point which can be opened 
for grouting at the desired depth by lifting the rod slightly. 

This tool has many good features. It is threaded to fit standard 
EW Drill Rod so that additional rods can be added as the tool is driven 
to the desired depth. A hammer head and a combination pulling-pumping 
had are available that fit into the upper threaded end of the tool. The 
same tool is also available with an expendable pump-out point for use 
when a full opening is desired for more viscous grouts. A pointed end 
permits the tool to be driven into the ground without becoming plugged 
in the process. The tight fit of the tool in the ground seals it to the 
soil, insuring that the grout is injected into the strata to be treated. 
Injection can be made in stages as the tool is driven in, or as it is 
being withdrawn after it has been driven to the full depth to be grouted, 



93 





Figure 53. Pump open drive point for grout injection. 

The use of this type of tool is limited to shallow depths and to 
loose or soft soil. Most companies will not use this type of tool below 
50 to 60 feet. Driving and pulling equipment must be available to use 
with this tool . 

2. Pipe in Boreholes 

This method requires injection boreholes to be drilled to the deepest 
point of grouting. The borehole is then cased and the drilling mud, a 
bentonite slurry used during drilling, is removed. The injection pipe, 
with an air inflatable packer on the end, is lowered into the casing. 
The casing is then raised to the upper side of the strata to be grouted 
and the packer set in the lower end of the casing. The lowest zone is 
then grouted. The casing and injection pipe are then raised together to 
the upper edge of the next zone and injection is made again. 

An alternate method is sometimes used when the soil is wery permeable, 
As the borehole is advanced, drilling is stopped at desired intervals, 
the drill pipe is lifted slightly and the grout is injected without using 
a packer. This method is not applicable unless the grout can be injected 
into the soil using only the head of the grout column to place the grout, 
so it would not be used very often. 



94 



Another alternate method would be to place plastic pipe containing 
holes or slots into the borehole and contain it with a gravel pack around 
the perforated section and a light grout above the gravel to seal off the 
hole. Injection would then be made into the pipe with the grout moving 
through the perforations. This method does not permit selective grouting 
nor give the operator control over the grout placement. 

3. Tube cf Manchette and Stabilator 

A third method is the use of specially made plastic injection pipe 
containing holes covered with a flexible restraining sleeve which 
expands under grout pressure^to allow the grout to flow out into the soil. 
One such pipe, called "Tube a Manchette", is an invention of Soletanche 
Entreprise, a French grouting firm. Figure 54 shows the principle of 
this pipe system. A threaded plastic pipe section about 12 inches (30 cm) 
long contains a ring of four holes of about one-half inch (1.27 cm) 
diameter in the center, covered by a rubber sleeve on the outside. Any 
desired number of these sections can be screwed on the end of a pipe to 
cover the area desired to grout. 

Figure 55 shows the steps in the grouting process using this system. 
The tube a manchette piping is placed in the completed cased borehole 
(Figure 55-2). The casing is then withdrawn (Figure 55-3) and a clay 
cement slurry known as, "sleeve grout" is poured or pumped into the void 
left around the tube a manchette piping. 

Then a small diameter grouting pipe, fitted with opposing cup-type 
or ring-type packers, is lowered into the outer sleeve (Figure 55-4). 
Grout injection is made selectively through the grout pipe between the 
packers. Pumping the grout expands the rubber manchette and forces the 
grout to fracture through the weak sleeve grout to permeate the sand 
strata. The grout tube can be moved as desired to place the packer 
section opposite the formation to be treated. Most European companies 
use this grouting system. 

A similar system was developed by Stabilator, a Swedish firm. It 
has been used in Europe and is now being used by some companies in the 
United States. This system uses a drill bit inside a steel extension 
tube which acts as casing for the hole being drilled. When the hole has 
been drilled to the desired depth, the ring drill bit is knocked off 
and the drilling rod withdrawn, leaving the outer tubing in place. This 
outer tubing contains apertures in milled slots which are covered with 
leaf springs to act as one-way valves. This arrangement is shown in 
Figure 56. Grouting is accomplished through an injection tube with 
double packers similar to the tube a manchette system. 

4. Other Types of Injection Pipes 

The only other type of injection piping that the writers found in 
use is that of the single-element tube a manchette used by a Dutch 
company. This system was explained in an earlier chapter and shown in 

95 



'&*• V-bt 




Double packer 

Wall of grout hole 

•Semi -plastic 
sealing sheath 
Pipe sealed into 
hole 
Rubber "Manchette" 

Grouting orifice 
Grouting pipe 
Double packer 



From Soletanche Entreprise. 
Figure 54. Tube a Manchette 



o 

§ 

'V-. 

. <? ( 

.• <? 

.'o 

. 

• • o 



© 



". 
. " 

0. 






Boring and casing 
or mud drilling 



. 
• o 

■%''■ 

- o.: 



® 



° o. 

• £. 

.o' ■: 



Inserting the tube 
a manchettes 




® 




© 



Sleeve grouting Injection by means 

of tube a manchettes of a double packer 
and withdrawal 
of casing 



From Soletanche Entreprise. 
Figure 55. Operational principle of Tube a Manchette 



96 




Tube 



Aperture 



Leafspring 



Fixed part of the leafspring 



Courtesy - Stabilator, Stockholm Sweden 
Figure 56. Stabilator valve tube. 
97 



Figures 14, 15 and 16. Its use is limited to applications where grouting 
is to be done at one specified depth for a thickness of approximately 
one meter. 



D. Monitoring Equipment 

Monitoring is an important part of the grouting operation. During 
the mixing of the grout, the grout components must be controlled to 
provide exact proportions of each in the final grout mix. This is done 
by a proportioning pump or by flow meters on the line from each pump 
(see Figure 13). Some grouting companies have the pumps electrically 
controlled to pump only the desired amount and then stop. Dry components 
are weigned or prepackaged to give accurate proportions. 

The grout injection pressure can be monitored by visual or recording 
gauges that can be observed by the pump operator. Flow meters on the 
grout pump discharge lines, or a calibrated tank on the suction side, 
can be used to determine the amount of grout injected in each hole. 

The monitoring equipment is normally a part of the equipment 
furnished by the grouting company. 



98 



7. GROUT INJECTION PRINCIPLES 



Grouting procedures are based largely on past experience. Injection 
theory, based upon idealized soil conditions, is helpful in planning for 
grouting, but present grouting practices are usually based upon operations 
which have been successful in the past. 

A. Theoretical Considerations 

For a typical grouting situation, pipes are placed into the formation 
to be grouted from either the ground surface, a tunnel or a gallery. Pipes 
are normally placed in a grid pattern. The distance between pipes must be 
such that the grout can travel at least half of the distance between pipes 
in order to place grout completely throughout the soil before the set 
occurs in the grout. The grout injection rate through the pores of the 
soil is dependent upon soil permeability, grout viscosity and grout shear 
strength. The permeability is measured with water and corrected for the 
viscosity of the grout. In the case of Newtonian (true fluid) grouts, the 
permeation of the grout is controlled by grout viscosity for any given 
soil permeability. The particulate (non-Newtonian) type grout has its 
flow controlled in the early stages by viscosity, but in the later stages 
by the grout shear strength. 

1. Mathematical Theory 

Equations based on flow theory can be helpful in preliminary studies 
of a grouting problem. However, the simplifying assumptions used in de- 
riving such equations generally preclude their use for anything but this 
purpose. The properties of a zone to be grouted may be appreciably altered 
by the placement of injection pipes or by previous adjacent grouting (38). 
The soil particle distribution is disturbed, which affects flow charac- 
teristics and permeability. Also, it is possible that the grout character- 
istics may change as it becomes contaminated by passage through the soil 
pores, either by dilution from groundwater or by suspended fines picked 
up from the soil . 

Considerable theoretical background exists for the analysis of seepage 
into wells. Grouting practice is essentially a special case where pumping 
is into rather than out of a formation, and most important for the analysis, 
flow normally occurs at single injection points rather than along a hole 
axis through a slotted screen or well liner. Neglecting the force of 
gravity, flow therefore is radial in three dimensions, and the shape of 
the grouted mass approximates a sphere with the tip of the grout pipe at 
the center. 

a. Water Saturated Soils 

From the equation for volume of a sphere, the volume of soil permeated 
by grout is: 

99 



V = 



77 r 



(32) 



where r is the maximum radial penetration away from the tip of the pipe 
(see Figure 57). The grout volume equals the volume of soil voids, V =nV 
where n is the soil porosity expressed as a fraction. The grout volume 
also equals the pumping time, t, multiplied by the average grout take Q 
in cfm. Substituting, 



nV = Qt = n -^- 77 r 3 



r = 



.620^ 



(33) 
(34) 



where 



r = radial distance of grout penetration, 

cm (feet)* 
Q = average rate of grout take, cm 3 (ft 3 )/min 
t = pumping time or gelation time, 

minutes 
n = porosity of the soil expressed as 

as a fraction 



English units are given in parenthesis, 



s 




-& W 



Figure 57. Schematic of grout principle 
100 



For Newtonian fluids, the Darcy Law for flow rate Q gives 

Qt = tAk i (35) 

where k is the permeability coefficient of the soil for grout. The soil 
y 

area A at any instant is the surface of the penetration sphere, A = 47rr 2 , 

and the average hydraulic gradient i is 

1 = f (36) 

where h is the head difference in feet of water. By equating Qt in 
equations 33 and 35, substituting for A and i, and solving for t, 

. n 2 
= 3k 9 h r 

As previously shown, the permeability coefficient k is related to that 
for water by the ratio of respective viscosities: 9 

. k^ , and 

K g " N 

* ■ I- * (37) 

where 

t = time, minutes 
n = soil porosity 
N = ratio of viscosity of 

grout to that of water 
k = soil coefficient of 

pe rmea b i 1 i ty , cm/mi n 

( ft /mi n) 
h = hydraulic head, cm (ft) of 

water 
r = radius of the grouted soil 

mass, cm(ft) 

While the above equation, attributed to Maag, is a relatively simple 
expression of the effects of viscosity, permeability, grouting pressure 
and radial distribution on grouting time, its use is not recommended for 
reasons illustrated later. One reason is that it ignores resistance of 
water outside of the grout penetration sphere, and therefore would probably 
underestimate the time t except in dry soils. More importantly, it assumes 
that i is constant along a radius, which according to equation 36 means 
that the grouting pressure should increase linearly with the grouting 
sphere radius. This is not necessarily true. 

In order to take these additional factors into account, the grouting 
flow rate Q at the surface of a grouted soil sphere of radius r is 

101 



Q = 4irr 2 V r (38) 

where V is the radial flow velocity or "flux" across a unit area of soil. 
The Darcy Law written in differential form for a unit area is 

V --k-l&- 

r 3r 

where the partial differential - t— represents the hydraulic gradient or 
head loss per unit of length, at Sny particular radius. Substituting for 
V in equation 38, 

2,. 3h 



integration gives 



Q = -4irr 2 k ^ 



r 47Tk r u 



That is, hydraulic head (h ) is inverse to radial distance r from the 
grouting pipe. If the pi pe radius is r , then h = h when r = r , from 
which the constant of integration C is r 



C h ' 47rkr 
o 



and 



h = A_ (1 -i-) + h (39) 



r 47Tk ^ r r o 



Equation 39 is applied both inside and outside the grout sphere of radius r. 

r 4 3 k /i A (40 » 

MS!*, - h r = 4^k(-T n -?j (41) 

where r n is the radius of the sphere of influence, beyond which the 
hydraulic gradient is unchanged. A physical picture of this is obtained 
by considering that within this radius the injection volume is compensated 
by raising of the water table. If r n is large, ]_ _. « 

r 

Equation (41) then becomes 

h = A- - (41a) 

r 4-rrk r 

Combination of equations 40 and 41a and solving for h gives 

102 



h = Q |W N - 1 1 (42) 

4^k [r r 

where 

h = grouting pressure at the tip of the pipe, 

cm (ft) of water 
Q = flow rate, cm 3 /min (ft 3 /min) 
k = soil coefficient of permeability, 

cm/mi n ( ft/mi n) 
N = ratio of grout viscosity to that 

of water 
r = radius of the grout pipe, cm (ft) 

r = radius of the grout (sphere), cm (ft) 

This equation was first developed by Raffle and Greenwood (43). Note that 
if the viscosity ratio N = 1, 

o 

That is, for a constant flow rate Q the pressure h is constant regardless 
of the grout penetration distance r and depends only on pipe radius r and 
soil permeability k. If the grout is more viscous than water, i.e., 
N >1 , equation 42 states that for a constant flow rate the pressure must 
increase with increasing grout penetration. 

The maximum pressure as r becomes very large is: 

h - QN (42b) 

n 4irkr 
o 

The above equations still do not show the time required for grout to 
reach a particular radius. In this case the rate of change in radius dr 
is a function of radial fluid flow rate V and fractional soil dt 
porosity, n: „ 

dr _ r 

dt n 

Substitution for V from equation 38 gives 

dr _ : Q 
dt " 4rnr rz n" 

The quantity -*- may be substituted from equation 42 

* = M r *N (I - I) * r I (43) 



103 




Rearranging and integrating gives 
hkt = 



NL%lfL r2 + r 



+ c 



The integration constant may be evaluated by noting that when t = 0, 



r = r . Then 
o 



hkt 




iUI r* - r* 



which is somewhat more conveniently expressed 



nr; 



t = 



hk 




- 1 




(44) 



A simpler equation results if at time-t = the grout radius is assumed 
to be 0. Then C = and 



nr 



t = 



hk 



N - 1 



\ 0/ \ o/ 

where symbols are as listed for equations 37 and 42. 



(44a) 



The three equations for grouting time arranged in order from most 
to least accurate are 44, 44a and 37. Since the equation simplicity is 
inverse to this order, some comparative results are presented as follows 
(Equations 44 and 44a are solved by r by trial and error): 

Example 1 - Case History - Exhibit A - BART Tunnel grouting. 

t = 0.5 minute (gel time) 

n = 0.41 

r = 1 in. = 0.0833 ft. 
o 

h = 50 psi = 7200 psf = 115.4 feet 

of water (assumed) 

k = 0.2 cm/sec =0.39 ft/mi n (assumed) 

N = 5.2 for chemical grout 

Solutions arranged from most accurate to least accurate are as follows: 



104 



Equations r, ft Q, ft 3 /min Qt, ft 3 

44 and 42 1.42 9.5 4.8 

44a and 42 1.42 9.5 4.8 

37 and 34 5.63 614 307 

As anticipated, equation 37 overpredicts the grouted radius in this 
example by a factor of 4 while the grout volume is overestimated by a 
factor of 65. Use of equation 44a in lieu of 44 did not change results, 
and the grout quantities indicated by equations 34 and 42 are fairly 
compatable if the same sphere radius is used. In this particular example, 
drilling showed the sand to be consolidated to a depth of about 1.5 feet 
per shot, so grouting was continued at 1.5 feet increments to about 6 feet, 

In some instances, including the example given above, grouting is 
performed through a surface such as a wall or tunnel lining, and the 
distribution thus approximates a hemisphere rather than a sphere. In 
this case the time-penetration relationships of equations 44 and 44a are 
unchanged, but the grout volume is reduced one-half. 

Example 2 - Case History - Exhibit D - Pregrouting for tunnels, 
Pontiac, Michigan. 

t = 10 min (assumed) 

n = 0.25 

r = 0.75 in = 0.0625 ft 

h°= 40 psi = 92.3 ft water 

k = 0.05 cm/min = 0.00164 ft/min (assumed) 

N = 2 for silicate grout 

Solutions are as follows: 

Equations r, ft Q, ft 3 /min Qt, ft r 



44 


and 


42 


0. 


844 





0617 





617 


44a 


and 


42 





844 





0617 





617 


37 


and 


34 


3 


01 


2 


86 


28 


6 



Again, equation 37 seems to overestimate grout penetration and amount. 
Equations 44a and 34 are recommended for general use. Actual radius used 
was 1.5 feet, so the theoretical approach probably can best be used as a 
guide for planning of a job. 

Analytical treatments are perhaps most useful for predicting the 
effects of modifications in practice. For example, what are the effects 
of increased grouting pressure, or increased radius of the grouting pipe? 

Example 3 - Same as Example 2, but (a) with twice the pressure, or 184.6 ft 
water; or (b) with twice the pipe radius, r = 1.5 in = 0.125 feet. 

105 



Solutions utilizing equation 44a for radius and equation 34 for amounts 
are as follows: 

Grouting Spec . r, ft Q, ft 3 /min Qt, ft 3 

Original 0.844 0.0631 0.631 

h x 2 1.059 0.125 1.25 

r x 2 1.075 0.130 1.30 

o 

It can be seen that either modified procedure should increase the grout 
radius about 25% and approximately double the "take" for the same pumping 
ti me . 

b. Injection from Slotted Pipe or Tube a Manchette 

Example 3 shows that the grouting rate could be approximately doubled 
by either doubling the pumping pressure or the radius of the grout pipe; 
however, allowable pumping pressure is limited by overburden pressure, and 
larger holes cost more to drill. The same effect of increasing the flow 
rate by increasing the area of the soil -grout interface can be achieved 
by grouting a short length of the hole, viz, either by raising the grout 
pipe prior to injection or by using a slotted pipe or packer injection 
device. This principle is widely recognized in well practice, where 
theoretical treatments show that radial two-dimensional horizontal flow 
to a slotted pipe is far more efficient than spherical flow to an open end. 
For a short exposed length L the exposed area is: 

Sidehole exposure only: A = 2 r L 

Sidehole + end hemisphere: 

A = 2?rr L + 2-rrr 2 
o o 

Dividing by the area used for derivation of the above equations, 2-nr* 
gives a correction factor for r : 

Sidehole: multiply r by — 

r o 

Sidehole + end: multiply r by(- + 1 



o " \r 



Example 4 : Same as Example 2, but with injection through Tube a Manchette 
one diameter long (Fig. 55), or with open drive point (Fig. 53) open one 
diameter, or with grouting pipe raised one diameter prior to injection. 





Effective 








Method 


r , ft 
0.0625 


r, ft 
0.844 


Q ft 3 /min 
0.0631 


Qt, ft 3 


Tip Injection 


0.0631 


Tube a* Manchette 


0.125 


1.075 


0.130 


1.30 


Drive Point 


0.125 


1.075 


0.130 


1.30 


Retracted Point 


0.1875 


1.243 


0.201 


2.01 



106 



It can be seen that any of these other methods increase the flow rate Q 

two to three times, increasing r or decreasing time t for a given grout 

penetration in a given time. The drive point and retracted tip calculations 
assume no caving of the hole. 

In summary, grouting equations such as 44a and 34 provide a valuable 
insight into grouting practices which have been arrived at more or less 
by trial. Equation 44a requires a trial -and-error solution for grouting 
radius r; usually in practice a radius is assumed based on prior 
experience. Equation 37, while simple and not requiring a trial -and-error 
solution, is quite inaccurate and should not be used. 

c. Effect of Dry Soils 

Grouting of dry soils means equation 40 can be applied directly except 
that h = 0. Equation 43 becomes 



dr hk 
dt n 

and if r = at t = 



-■" \ - * 



-1 



(45) 



t = 



nr: 



nk 



3 r 



N (r 
2 r 



o 



where symbols are as before. x 

Example 5 . Same as example 2, but with grouting into dry soil, 
gives: 



(46) 



Solving 



Condition 

Saturated 
Dry 



r, ft 

0.844 
0.860 



Q, ft /min 

0.0631 
0.0667 



Qt, ft 

0.631 
0.667 



The difference is relatively minor. Another factor is that the loss of 

buoyancy will cause greater sinking of the grout. The vertical hydraulic 

gradient on a bulb of grout due to gravity is the head loss per unit 
elevation: 



Dry Soil, i y = G 
Submerged Soil, i = G -1 

where G is the specific gravity of the grout. Note that if G = 1 the 
gradient in dry soil is 1.0, and in submerged soil 0; in the latter case 
no gravity flow will occur. The relative importance.of gravitational 
head can be seen by comparison to typical values of— — - the gravitational 
head is relatively small, so the effect of gravity is negligible over short 

107 



times. If however, setting is delayed for a long time, gravity will pull 
the grout downward in accord with the Darcy relationship. The distance 
of sinking S is velocity times time, or with other symbols as above, 

Dry soil: S = £ tG (47) 

Saturated soil: Neglecting the viscous 
resistance of water displaced, 

S = |t(6-1) (48) 

Example 6 . Same as example 2, but G = 1.2 and t = 5 hours. 

Dry: S = °- Sj 164 (300) (1.2) = 0.30 ft 

Saturated: S = 0,Q ^ 164 (300) (0.2) = 0.05 ft 

Thus, even with a prolonged setting time, grout sinking would be small 
or negligible. 

d. Non-Newtonian Grouts and the Limiting Sphere 

The above considerations apply to ideally viscous grouts, that is, 
where shearing stress is proportional to the rate of shear. Many common 
grouting materials also exhibit a threshold or yield stress (or minimum 
shearing stress) to cause flow, above which the flow rate and shearing 
stress again become proportional, as shown in Figure 58. A yield stress 
dictates the maximum distance of penetration, since a minimum pressure is 
necessary to drive the flow, and pressure decreases with increasing sur- 
face area of the penetration sphere. 

In ideal Newtonian flow, Figure 58, Curve A, the rate of shear is 
proportional to shearing stress, t: 

Newtonian: -r~ = - — ' ( 49 ) 

dy y 

u being the viscosity. For ideal plastic flow, curves B and C of Figure 

58, the rate of shear is proportional to shearing stress in excess of the 

yield stress, t : dv x t-t (50) 

J Plastic: - - - 

dy y 

Curves B and C of Figure 58 are drawn to illustrate the phenomenon 
of thixotrophy, characteristic of many grouts, and especially those con- 
taining bentonite. Setting time allows particles gradually to become 
oriented for optimum exercise of electrical attractions, such that the 
grout thickens as indicated by an increase in yield stress. Stirring 
temporarily disrupts the bonds, renewing the fluidity. A practical impli- 
cation would be if pumping stops for a few minutes during injection of a 
thixotropic grout, it may be difficult or impossible to start again with 
out exceeding established maximum pressure. 

108 



NEWTONIAN 
FLOW 




SHEARING STRESS. 1" 



Figure 58. Newtonian vs. plastic flow. 



Figure 59 illustrates how the Hagen-Poiseuille derivation for laminar 
flow through a cylindrical tube equates driving pressure ydh times circular 
cross-sectional area Try 2 , with resisting shear stress t times cylindrical 
area 2iry dx: 



where 



Try 2 dh = 2*ny x dx 

Y = unit weight of water, so 



T 2 



_dh 
dx 



(51) 



Therefore, shearing stress is zero at the middle of the tube (y = 0) and 
varies directly as the distance from the center, increasing to a maximum 
at the boundary. 



D 



Substitution of y = j where D is the pore diameter gives 



t max 



D ydh 
" 4 dx 



(52) 



109 



at the surface of the pore. For the case of plastic flow x must exceed 
the yield stress t , from which 



dh 



dx 






mm 



5 

qD 



(53) 



where 



T = 



y 

D 



minimum hydraulic gradient 
for flow 
yield stress 



= pore diameter 



That is, flow will cease when the hydraulic gradient falls below a value 
dictated by the grout yield stress and the soil pore diameter. In 
spherical or radial injection, the hydraulic gradient decreases with 
increasing penetration distance; hence, grout having a yield stress also 
will have a limited penetration into soil or rock pores. The same is 
true for drilling mud in wells, where low penetration is an advantage. 



HEAD DIFFERENCE-dh 



-T777/ //////// 




Figure 59. Force affecting flow of a fluid element in a 
cylindrical tube of diameter D. 



The effect of a yield stress on flow velocity is illustrated by a 
general consideration of the forces in Figure 59. If the yield stress is 
zero, i.e., the fluid is Newtonian, the variation of x across a circular 
capillary is shown in Figure 60(a) corresponding to equation 51. Toward 
the center of the capillary, the shearing stress reduces linearly to 
zero. The same relation applies if the fluid exhibits a Bingham yield 
stress, except that in the center of the tube where x < x.., the mass will 



behave as a plastic surrounded by a liquid shield, as in 

110 



Figure 60(b). 



(a) 
NEWTONIAN FLOW 

(Ty=0) 

r 



(b) 
BINGHAM FLOW 

lTy>CT) 




LIQUID 



SHEARING STRESS T, 
gm (FORCE) /cm 2 



LASTIC 
SOLID 




LIQUID 



SHEARING STRESS T, 
gm (FORCE)/cm 2 



(c) 
NEWTONIAN FLOW 




(d) 
BINGHAM FLOW 




CORE BEING 
PUSHED ALONG 



25 ' 25 

FLUID VELOCITY V , cm/sec FLUID VELOCITY V ,Cm/sec 

Figure 60. Comparison of shearing stress and velocity. 



Ill 



The existence of a solid core being transported does not change the relation 
of equation 51 outside of the core, but inside x will be zero. 

The flow velocity v in the tube (Figure 60) is obtained by combining 
equations 49 and 51 and integrating with respect to y. For Newtonian 
fluids, 



Y, 



V = 



w dh 
4y dx 



-r 



(54) 



This is the equation of a parabola, shown in Figure 60(c) for water under 
a unit hydraulic gradient (y w = 1 gm/cm 3 , u = 0.01 gm/ cm-sec, dh/dx = 1). 

A similar combination of equations 50 and 51 for fluids with a yield 
stress gives 



v = 



T w dh 

4y dx 



- r 



or 






(55) 



(56) 



A graph for a fluid similar in other respects to water but with a yield 
stress Ty = 0.2 gm (force)/cm 2 is shown in Figure 60(d). The above 
function is discontinuous at t = i y ; which means from equation 51 that 
it applies only when 



Y 



dh. 
dx 



As can be seen from the graphs of Figure 60, the yield stress of a 
fluid tends to: 

(1) Reduce injection velocity 

(2) Give a central core of plastic material 
supported and pushed along in a surrounding 
liquid 

(3) Present a maximum injection distance for a 
particular pore size, because of the decrease 
in hydraulic gradient with radial or spherical 
penetration 

The exact prediction of penetration rate and maximum radius is not 
a simple matter since they depend on the hydraulic gradient at the grout 
front. This could be found from flow rate if the Darcy law were valid. 
However, as shown by equation 55 and its discontinuity, flow velocity is 
not simply a constant times the hydraulic gradient dh/dx; in the peripheral 



112 



ring, the gradient is partly utilized to overcome the yield stress while 
the core is carried in nonviscous flow. A valid theoretical equation 
could be developed, but has not been. A further complicating factor is 
thixotrophy, commonly present in non-Newtonian grouts, which would allow 
gradually stiffening core material to act as a stoppage in channel 
restrictions. 

2. Theory of In Situ Stress Modification by Grouting 

Pressure grouting changes existing stresses in soils and fractured 
rocks to the extent that their stability may be affected prior to grout 
setting . For example, grouting adjacent to a basement, retaining wall or 
other rigid substructure may temporarily or permanently increase lateral 
load on the structure. Grouting tends to equalize in situ compressive 
stresses and relieve shearing stresses; this may be an advantage prior 
to excavation or tunneling, or may be a disadvantage where shearing 
stress is required for stability, as in an active landslide. 

Modification of in situ stresses by grouting occurs in three ways: 

(1) Seepage Forces . These represent frictional restraint to the 
flow of grout, and therefore exist only during actual grout flow. Stresses 
should relax immediately as pumping stops, when a small reverse force and 
flow may even occur due to (a) compressibility of pore air or, (b) rebound 
of an expanded soil structure. Seepage forces are temporary; they are also 
directional, opposing the flow direction and thus extending radially from 
the grout pipe, and they are distributed throughout the affected soil. 
Seepage forces tend to compact affected soil and decrease permeability 

and flow, as already discussed, but otherwise they probably are not of 
major significance. 

(2) Hydrostatic Pressure . Grouting of unsaturated soils introduces 
a hydrostatic head by filling the pores with a fluid. This can be quite 
significant if it occurs in soils normally unsaturated, as behind retaining 
walls. Grouting of saturated soils increases hydrostatic head only 
moderately, by raising the head or by the grout being heavier than water. 

(3) Pore Pressure . Hydrostatic pressure in excess of that from the 
standing head will build up during grout pumping, and can be relieved 
only by escape flow. If the escape is impeded by low permeability or 

by setting of peripheral grout, pore pressures may remain intact while 
the grout sets, and remain as a permanent modification of in situ stress. 

The relation between total pore pressure and intergranular stress 
is shown in Figure 61. When intergranular stress is expressed on a gross 
area basis, pore pressure subtracts to give "effective stress": 

a' = a - u (57) 

where a 1 is effective intergranular stress 
a is total stress 
u is pore pressure 

113 



«r 



SOIL PORE 




^ * A A~* 



*7 



Figure 61. Pore pressure effect on stress 



After the grout sets, the residual pore pressure is frozen as a grout- 
to-soil grain pressure, and it is no longer truly hydrostatic since the 
pore material then can sustain unequal compressive stresses and shearing 
stress. That is, after setting, u becomes a matrix stress which is part 
of and not differentiated from the total stresses a l9 a 3 , etc. The pore 
pressure prior to setting is the major concern. 

A careful distinction is necessary between pore pressure arising from 

hydrostatic head and that due to grout pumping. For example, raising the 

hydrostatic head pore pressure by submergence increases the total stress 

as well as the pore pressure, leaving the effective stress unchanged. 

Therefore, soils at the bottom of the sea, although under a very high 

stress and pore pressure, remain soft and unconsolidated, since the 

effective stress is the same whether under deep submergence or under shallow 

submergence. In contrast, since raising the pore pressure by grouting 

causes no proportionate increase in confining stress [a x and a 3 in Figure 

61), the effective stress is reduced. The discussion will include the 

following symbols: 

u = total pore pressure 

Au = that part of u derived from grout 

pumping pressure 

o = total stress 

o*'= net effective stress 

a - (u - Au) = effective stress 

due to buoyancy and exclusive of 

pumping pressure. 

114 



a"= 



Stresses in a solid can be defined in terms of three principal 
stresses, designated a ls a 2 , and o 3 , acting on three mutually perpendicular 
planes that are devoid of shearing stresses. The maximum and minimum 
(designated major and minor) principal stresses a t and o 3 plotted on an 
abscissa, with their difference used as the diameter of a circle, Figure 62, 
allows a graphical evaluation of shearing and compressive stresses on any 
plane in the solid. Mohr failure theory says that when the circle is 
large enough to contact a failure envelope, the material will fail in 
shear along a plane at a direction 6 with the major principal plane. 
The values of shearing and normal stress x f and a on this plane are as 
shown. 







MOHR CIRCLE 



COMPRESSION 



C COT 



Figure 62. Relation between principal shearing 
and normal stresses. 



The effect of a grouting pore pressure Au on effective stresses is 
shown in Figure 63. Since u subtracts from all compressive stresses, the 
effect of a high water table is to shift the Mohr circle to the left, 
as from position A to position B in the figure. If the additional grout- 
ing pressure Au is large enough (position C), failure will occur, which 
in confined soil implies only a readjustment of internal stress as the 
affected soil shears and compresses in response to the major principal 
stress. This is a departure from the conventional theory for measurement 
of horizontal in situ stress by hydraulic fracturing, where it is assumed 
that failure is in tension along vertical planes (46). The zone of soil 
most affected should be below the grout pipe, where downward seepage 
forces combine with soil pressure to give the largest principal stress. 
Shearing of granular soils often involves an increase in volume (dilatancy), 
in which case pores will minutely expand, accept more grout, and reduce 
the grouting pressure. Alternately in loose materials shearing may de- 
crease the volume, sealing against further entry of grout, increasing 
pressure and tending to create a void around the grout pipe. In both 
cases, the change in soil structure should change the failure envelope 

115 



such that either less or more pressure will be needed to sustain the 
failure; thus, a sudden pressure change may be a clue that failure is 
occurring. It should be noted that efforts to increase grouting pore 
pressure beyond the point of failure will enlarge the failure zone or 
cavern, with potentially dangerous consequences, particularly in shallow 
grouting. 



OVERBURDEN 
1 PRESSURE 




PORE PRESSURE fj. 



Note I Grouting pressure Au theoretically may induce soil shear 
failure. Inset shows overburden pressure (arrows), and 
hypothetical failure zone and shear directions. 



Figure 63. Effect of grouting pore pressure effective stresses 



116 



a. Grouting Pressure to Induce Shear Failure 

The relationships of Figure 63 can be used to predict grouting 
pressure sufficient to induce soil shear failure. Under ordinary con- 
ditions the major principal stress a x is vertical and the result of over- 
burden pressure. Therefore at depth h, 

ax = yh (58) 

where y is the soil unit weight. In soil below a water table the effective 
stress is reduced by hydrostatic pore pressure 

a." = Y h - y w (h - hj (58a) 

where t w is the density of water and h w is the depth of the water table 
below the ground surface. A grouting pressure Au further decreases the 
effective stress, and in Figure 63 can be seen 

Oi = a" - Au and 

a' = a" - Au (59) 

3 3 x ' 

Figure 63 is for a cohesionless soil, which means for the failure condition 
the Rankine stress ratio K' of lateral pressure to vertical pressure is: 

i 

K' = = 1 : sin (j) 

aT 1 + sin (j, (60) 

Substituting from equation 59, 

„, . ol - Au _ 1 - sin (j) / An y 

K -i^-Sa" 1 + sin cj) (60a) 

which may be solved for Au: 

A _ a 3 (1 ± s1nd>) - a? (1 - sjnj ) (61) 

2 sin cj) 

Thus the grouting pressure to u cause failure depends in part on the in situ 
effective horizontal stress a 3 \ which usually is not known. M In the special 
case where horizontal stress equals vertical stress, o 3 = a x , equation 61 
reduces to 



Au = a" (61a) 



ii 



per usual grouting practice. However, a 3 usually is less than a , 
particularly in geologically recent soils that are normally consolidated; 
that is, the horizontal stress has developed as a consequence of con- 
solidation under the existing overburden pressure. The ratio c^'/a" is 
commonly designated K , the coefficient of earth pressure at rest. 



117 



Substituting a 3 = K a x in equation 61, 

AU= ;' K °° + Slnt | lilf S ™* (62) 

An empirical equation by Jaky for K of normally consolidated soils is 

-p-= K = 1 - sin <f> (63) 

i 

Substituting, . \ 

Au = a ;(l^s1ni) (64) 

In the case of cohesive soils the failure envelope is shifted to the left 
by an amount c cot <j> (Fig. 62), indicating an additional pore pressure in 
this amount. The general equation for normally consolidated soils with 
or without cohesion is therefore 

Au = ff ; LiiM + c C ot <-, (65) 

where Au = grout pressure which allows soil 

shear failure 
a" = overburden pressure less buoyancy 
<j> = soil angle of internal friction 
c = soil cohesion 

Example 1 : An alluvial soil has y = 130 pcf, <J> = 30°, c = 4 psi. Find 
the grouting pressure to cause shear failure at a depth of 80 feet, the 
water table being 10 feet below the ground surface. 

Solution : Using equation 58a, 

a" = 130(80) - 62.4 (80-10) = 6032 psf 

Assuming normal consolidation, using formula 65, 

i = 6032 1 ] ~ * in 3Q j + 4(144) cot 30 

= 1508 + 998 = 2506 psf = 17.4 psi 

Note that despite the contribution from soil cohesion this is consider- 
ably less than the overburden pressure a", and is in fact less than the 
calculated a!J (equation 63): a5 = a! (1 - sin4») = 6032(0.5) = 3016 psf. 

In summary, grouting pressure, through development of soil pore 
pressure, may initiate shear failure of soil under its own weight, even 
when the pumping pressure is considerably less than the overburden stress 
reduced for buoyancy. In normally consolidated cohesionless soils, 

118 



the relationship between failure grouting pressure and effective over- 
burden pressure is approximated by 1/2 (1 - sine})), with values as follows 



Table 


8. 


Relationship 


Betweei 


l Fail 


ure Grouting 


Pressure and 


Effective Overburden 


Pressure 


All 




9 - 

1 - si no 
2 



0.50 


5 
0.46 


10 
0.41 


15 
0.37 


20 
0.33 


25 
0.29 


30 
0.25 


35 


40 
(0.18) 


45 


(0.21) 


(0.15) 



This relation introduces an apparent anomaly: the higher the internal 
friction angle the lower the grouting pressure necessary to induce failure. 
It is true that in normally consolidated soils, high friction angles result 
in low lateral confining pressures. However, <j> values in excess of about 
30° probably are a result of overconsolidation, where the Au/ai' ratio 
may approach 1.0. The analysis does indicate that shear failure must 
routinely occur during common grouting practice of normally consolidated 
(i.e. soft or loose) soils, and therefore must relate to injection of 
grout in these soils. However, it should be emphasized that this has 
not been verified by laboratory or field test data. 

b. Grouting Pressure Against Walls 

Grouting seldom is attempted behind a retaining wall other than 
soldier beam and lagging because of the unevaluated pressure effect on 
the wall. For instance, let us assume that soil behind an existing wall 
is to receive a surcharge loading of sufficient magnitude that the wall 
will fail if not given additional support, as by buttresses or tiebacks. 
A possible solution might be to grout the soil behind the wall to increase 
the soil strength sufficiently to carry the surcharge without additionally 
loading the wall. But how will the grouting process itself affect 
stability of the wall? 

Example 2 : A 20-foot wall retains soil with y = 120 pcf, c = 0, (J) = 25°, 
under drained conditions. The grouting pressure will not exceed one-half 
the present overburden pressure. 

Solution : (1) Calculated pressure distributions are shown in Figure 64. 
Prior to grouting (47), the force on the wall (see Figure 64a) is: 

P = \ Y m H 2 K 1 - 2 cHVk 7 " (66) 

where 1 - sincfr 

K 1 + sin<j) 

y = wet unit weight of soil 
'm 3 

H = height of wall 
119 



WALLx 



SOIL 



yr^y/^TW 7 ^ 




NET OVERTURNING 
FORCE P= 9741 LBS. /FT. 



500 1100 PSF 

SOIL LOAD WITH INTERNAL 
FRICTIONAL RESTRAINT 



(A) 

BEFORE 
GROUTING 



ZERO GROUTING 
PRESSURE 
P=20,446 LB/FT 




(B) 

DURING GROUTING 

"7 



SOIL PRESSURE 
LESS BOUYANCY 



2000 

HYDROSTATIC 
PRESSURE 



GROUNTING PRESSURE 
SUFFICIENT TO INDUCE SHEAR. 



Ps27,000 LB/FT 

PLUS GROUNTING 




N^ 



1,000 2.000 

SOIL PLUS GROUT 
HYDROSTATIC PRESSURE 



P + P - 39,000 
LB/FT(EST) 



3,000 



(C) 

AFTER GROUTING 



20,000 PSF SURCHARGE 



WALL 



> ,LU U U 



-fe» 



'-'-i 



RESTRAINT FROM 






GROUT CEMENATION 



P=0. F. S.^2.3 



SURCHARGE 



LOAD ON 
WALL 







SOIL PRESSUf 



Figure 64. Soil pressures on a retaining wall. 

120 



Substituting, 



P = |(120)(20) 2 (0.406) - = 9741 lb/ft 



(2) Saturation of the soil with grout will introduce hydro- 
static pressure on the wall, varying from zero at the ground surface to 

Y H at depth H, y being the density of the grout. The total hydro- 
y y 

static force is the average pressure times the height of the wall: 

v \ v 2 (67) 

Partly offsetting this is reduced soil pressure on the wall due to buoyancy, 
so y m in equation 66 is replaced by (y m - Yg). Thus for the submerged case, 
equation 66 becomes 



P g = \ (Y m ' ^ H " K ' " 2c "^~ + \ Y g H 2 (68) 

he soil density after grouting is 135 pcf, 

P = \ (135 - 80) (20) 2 (0.406) - + \ (80) (20)' 



If y q = 80 pcf and the soil density after grouting is 135 pcf 



= 4446 - + 16,000 
= 20,446 lb/ft 

This pressure distribution is shown at the left in Fig. 64b. It represents 
a theoretical minimum exerted wall pressure, and is not appreciably different 
from what would occur if the soil were saturated with water [y = 62.4 pcf). 

(3) The grout pressure to cause soil shear failure using 
equation 65 is: 

Au = a" M - sin 25 . 



If the grouting pressure equals 0.5 o r the soil will be in shear, separating 
soil grains and thereby decreasing § to and increasing K 1 to 1.0, and 
disrupting soil cohesion. From equation 66 with K' = 1 and c = 0, 

P g = \ (135) (20) 2 (1) - = 27,000 lb/ft 

from soil plus grout hydrostatic pressure on the wall. This represents a 
practical minimum, shown to the right in Figure 64b. (note that when the 
soil is shearing, grout hydrostatic pressure is not separable from soil 
pressure and is not added). 

(4) The grouting pressure Au puts an additional force on 
the wall, and one that is less well defined because of dissipation when 
pumping stops. If pumping continues until setting, the pressure may 
remain. The maximum force therefore is defined by an equation for grouting 
pore pressure, P , analogous to equation 67. 

r 

121 



P p = f H 2 C u (69) 

where C is a pressure dissipation coefficient. The maximum grouting 
pressure may increase with depth; in this example Au = h a lt giving 

where a x = yH. Then 

P p = l yH3C u = i (120)(20) 3 C u 
= 240,000 C lb/ ft 

The coefficient C u would be minimized through proper grouting pro- 
cedures, i.e., grouting first close to the wall and then farther back, 
and stopping pumping sufficiently prior to set to allow dissipation of 
pore pressure. Figure 64-b assumes C u = 0.05. Note also that the grout 
pumping pressure is concentrated at the base of the wall, giving lower 
overturning movement. 

In summary, the minimum additional force on the wall from grouting 
is 27,000 lb/ft; the maximum with full activation of grouting pressure 
is 240,000 + 27,000 = 267,000 lb/ft, an increase almost by a factor of 
10, but this would not occur if procedures are designed to dissipate 
grouting pore pressure prior to set. 

Example 3 : After grouting, the soil has <j> = 30°, c = 100 psi and y s = 135pcf. 
A surface surcharge load of 20,000 psf is planned. What is the final force 
on the wall? 

Solution : If q is the surcharge load, the additional pressure is q K, 
and the additional force q_KH. Adding to equation 66, 

P = \ y H 2 K - 2cH Vi< + q KH (70) 

2 s s 

= 9000 - 332,550 + 133,300 = -190,220 

or in effect P = 0. For comparison, equation 70 solved for the soil with- 
out grouting gives P = 9741 - 10,193 + 162,340 = 161,890 lb/ft. The 
factor of safety with grouting is: F.S. = resisting force * acting force = 
332,500 t (9000 + 133,330) = 2.3 for zero pressure on the wall. 

c. Grouting Pressure in Tunneling 

The theoretical analysis suggests that grouting soil or rock prior to 
tunneling could have beneficial effect on stress distribution, in addition 
to strengthening loose materials and sealing off water. The main advantage 
would be in heavily overconsoli dated soils or in rocks subjected to 
tectonic stresses such that the in situ horizontal stress exceeds the 

122 



vertical stress. Equation 61 still applies, except that o t is horizontal 
and o 3 vertical. Although the horizontal stress is seldom known with any 
precision, a grouting pressure equal to the overburden pressure should 
allow relief of excessive horizontal stresses where they exist. The 
advantage would be a reduction of horizontal residual stress which tends 
to cause lateral closure during tunneling or drilling operations, and 
subsequent wall spall ing and rockbursts (48). 

d. Landslides 

In contrast to foundation grouting, active landslides represent a 
delicate balance between downslope components of soil weight plus ground- 
water seepage, versus resisting shearing stresses in soil along the 
failure zone. Any reduction of a critical shearing stresses by grouting 
pressure thus will speed up movement and could precipitate a disaster. 
Grouting, if attempted at all, must be at a low pressure and with fast- 
acting chemicals. Preferred methods are to control water through use of 
drains, wells or electroosmosis, or the use of dry water-reacting 
chemical such as quicklime(49) . 

e. Foundation Grouting 

Grouting pressure conceivably could cause temporary failure of soils 
under existing foundations, although such occurrences have not been 
reported because of the time and care required and the sequential nature 
of grouting operations. Furthermore, remedial grouting can be performed 
to correct differential settlements or vibrations, or in anticipation 
of heavier loading, without significantly affecting an existing high 
factor of safety against shear failure. The grouting of an underdesigned 
foundation, which did not take into account a high water table, could 
become a critical operation; however, with normal operational care, 
failure would be unlikely after some grout has been placed and allowed 
to set. 



B. Practical Aspects 

1 . Grout Penetration 

Most grouting specialists base their grouting procedures and planning 
on their prior experiences and on the soil properties. The grout used is 
generally one which they have used successfully and in which they have 
confidence. Since the permeation of the chemical grout is controlled by 
its viscosity and the permeability of the soil deposit, the grouting 
specialist can have a general idea of the setting time needed to reach 
a desired radius of penetration from the injection point. 

If a non-Newtonian, particulate grout having shear strength is pumped 
under constant pressure into the soil, the opposing drag, due to the 
corresponding shear stress acting at the growing area of the surface 
wetted by the grout, ultimately becomes equal to the whole of the applied 

123 



pressure so that none is available to maintain the viscous flow. In other 
words, grout slurries of ordinary Portland cement and water can reach a 
point during injection when the pressure must be increased in order to 
keep the grout moving. Since the pressure should not exceed the over- 
burden pressure, there is a limit of penetration for the particulate 
grout. 

Table 9 gives calculated values of the limiting penetration radius 
for soils with permeability of 1, 10" 1 and 10" 2 cm/sec at an injection 
head of 100 feet (30.48m) (43). For cement grouts, the calculation 
cannot profitably be considered for less than k = 1 cm/sec (open gravel) 
because permeation is thereafter limited by the direct blockage of voids 
by the larger particles of cement. 



Table 9. 


Limiting Soil Penetration for Cement Grouts (43) 


Shear Strength 
(dynes/cm 2 ) 


Limiting Penetration for 100 ft 
of Injection Head (feet) 


Corresponding 

Water/ Cement 

Ratio for O.P. 

Cement 




Permeability, cm/sec 






k = 1 k = 10" 1 k = 10 -2 




67.6 

25.6 

6.6 


14.1 4.68 1.7 

11.73 3.9 

14.3 


0.4 
0.5 
0.66 



When using clay (bentonite) type grouts, the initial rates of shear 
involved in mixing and pumping the grout may reduce the shear strength to 
as low as 2 dynes/cm 2 at the time of injection; therefore the grout begins 
to penetrate the soil at a rate determined by the effective grout viscosity. 
When the penetration reaches the point that the rate of shear falls con- 
siderably, the grout shear strength increases rapidly and the penetration 
then becomes dependent on shear strength similar to that shown for cement 
in Table 9. 

The amount of grout to be used can be found by using the graph in 
Figure 65. This is true for any type of grout used, but it would not be 
correct if the grout is injected at a pressure which causes fracture of 
the soil formation. As fractures occur, so many channels become excessive 
and the operator cannot know where the grout is being placed. 



124 























POROSITY 


100% 






33% 25°/ 


o 15% 




lUU 
























Z7 








z_ 


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yu 
























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80 
























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to 4 . 














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2 3 4 5 6 7 8 9 10 20 30 40 50 60 

PENETRATION IN INCHES BEYOND GROUT POINT 



80 100 



Figure 65. Grout volume required to fill pore space radially 

around grout point. 

2. Grid Patterns 

The pattern for the grout injection is planned so the area to be 
grouted is completely covered. The grid pattern is normally based on 
data obtained from preliminary work and the purpose desired to be 
accomplished. Effective spacing of the injection points is governed by 
the type of grout to be used, grout viscosity, soil permeability, injection 
pressure and rate of grout take. Spacing radius can be determined by use 
of equation 34. The grouting is usually done from the surface if conditions 
permit; but it can be performed from cellars, from shafts, or from within 

125 



a tunnel excavation. A typical grid pattern for a waters top application 
is shown in Figure 66. 



/ y'/T'V THEORETICAL GROUT PATTERN 



K1.8A *| 



v ^jT' \\/ 1.5*. 

o i p I o 



#_'' 



\ 

o 



Figure 66. Typical grid pattern for waterstop application. 

Tests by Karol (38) have shown that a single row is not sufficient 
to give overlapping in the soil between holes. Therefore, by the use of 
two rows, or three rows with the center row offset as shown above, the 
grout will intermingle to give complete coverage. 

Grout is normally injected into alternate pipes in row 1 for the 
length of the row (#1, #3, etc.), then pipes in Row 1 between the odd- 
numbered pipes are used for injection. Grout injection then is made in 
the second row of pipes, following the same procedure as used in Row 1. 
If three rows are used, injection is made in row 3 after row 1; then 
injection is made in successive holes in row 2 to fill the voids left 
between the grout placed on rows 1 and 3. 

Figure 67 is an elevation view of the grout pipe spacing used to cover 
the desired width on a portion of the Vienna subway. Treatment was made 
both from ground surface and from cellars. 

The grouting in the downtown section of the Metro system in Hanover, 
Germany was done radially from shafts sunk at intervals along the proposed 
route of the tunnel, as shown in Figure 68. From these shafts, grouting 
was performed under the streets and adjacent buildings to strengthen the 
soil to prevent settlement when the tunnel is excavated below the building. 
Alternate pipes were used for injection, then the remaining pipes were 
used. In courtyards behind buildings, grout pipes were placed from the 
surface as shown in Figure 69 to supplement the radial grouting from the 
shaft. No apparent grid pattern was used, but pipes were placed both 
vertically and angularly to fill in spots not covered from the shaft. A 
Tube a Manchette system of grout pipes was used with a silicate type 
chemical grout. 

126 



Cross section D-D' 



+ 17 50 




Figure 67. Typical grouted section for strengthening soil 



BUILDINGS 



CITY 
STREET 




^-GROUT PIPES 
RADIALLY 



Figure 68. Schematic of grouting for Metro system in Hanover, Germany 

127 




Figure 69. Soil grouting for Metro system in Hanover, Germany. 



3. Job Planning 

Most of the grouting specialists interviewed seem to think that 
cement grout should be used ahead of chemical grout if the soil perme- 
ability permits. This procedure uses the cement grout to fill any large 
voids or pore spaces before the chemical grout is injected to fill the 
smaller remaining voids; thus, the use of the more expensive chemical 
grout is minimized. In actual field operations, the pressure required 
to inject the cement grout often becomes higher than overburden pressure 
and fractures the formation, thereby placing stringers of cement grout 
throughout the sand rather than permeating the voids in the sand for- 
mation. If there are utility pipes in the area which have voids or loose 
soil around them, the grout will seek this path after fracturing the soil, 
and will continue to flow along such path until set occurs. In the case 
of a chemical grout, this would involve a large quantity of grout if 
pumping were continuous. 

A grouting specialist will generally follow the same injection pro- 
cedure for all of the jobs performed, whether the end result will be for 
water shutoff, soil consolidation or soil strengthening. The difference 
would relate to the grout selected for the job. Theoretically, a weaker 
grout can be used if only water control through soil impermeability is 
involved. This concept is generally followed. 

128 



The placement of a grout curtain across an area to prevent water 
movement is accomplished by injection in boreholes or through drive pipes. 
When injection is performed on a grid pattern, a curtain of sufficient 
width can normally be obtained using three rows of injection holes with 
the center row offset so holes are centered between holes in the adjacent 
rows. The length of the curtain must be sufficient to reach across the 
path of water movement and deep enough to reach an impervious layer. 

In dam construction, grout curtains are used extensively for water 
cutoff walls. Many of these are in rock or coarse alluvial soil where 
cement grout or a combined cement-clay grout can be utilized; but the 
use of chemical grouts in the alluvial soils is becoming more common, 
especially after injection of cement grout. Grout curtains can also be 
used to prevent water flow into an excavation for tunnel or cut-and-cover 
construction. Water intrusion into an excavation causes "quick" conditions, 
resulting in lowering the water table which could cause subsidence of 
ground or settlement of adjacent buildings. 

Although grouting is useful for water control in underground con- 
struction, most grouting in this type of construction is used to consoli- 
date or strengthen soil. For this type job, site conditions will determine 
the location from which the injections can be made. It is generally better 
to drill the holes and perform the injection from the ground surface, but 
this is not always possible. Less desirable conditions for mixing and 
pumping the grout may be a factor for increased costs or for longer grout 
set time. 

Pumping tests on the site should be made to determine rate of in- 
jection. Water, or a tentatively selected grout, may be used for the 
test. As a "rule of thumb," the pumping rate which can be maintained 
with water at about one-half of the allowable pumping pressure (one psi 
per foot of overburden is normal) should be used. This would allow a 
safety factor for injecting the more viscous grout during the job. 

The time in minutes required to perform the injection in each hole 
can be determined by the volume of grout required per foot of sand con- 
solidated (from Figure 65) multiplied by the depth of sand to be treated 
then divided by the injection rate in gallons per minute. More precisely, 
this is: 

(Per HnlM t minute - Grout (gal s/ft) x depth of sand (ft) ,,,* 
(Per Hole) t, minutes Inj. Rate (gal/min) (71) 

The grout set time ts can also be determined by dividing volume of 
grout per foot (from Figure 65) by the pump rate, then multiplying by 0.5, 



or 



= Grout (gal/ft) , (72) 

TZl Ds+- n ( r,-*-\ /mini * U,J \ ' <- I 



set time, t s i n j. Rate (gal/min) 



The constant (0.5) is used so that the grout will begin to set when 
half of the volume has been injected, thus forcing the grout to distribute 
itself over a wide area rather than following the first part of the grout 

129 



into the more open pore spaces. If flowing water is present, the multiplier 
constant should be reduced drastically, perhaps to 0.1 or less, to let the 
grout set before it can be washed out of the formation to be grouted. 

C. Injection Quality Control : 

The quality of the grout operation is equally as important as the 
quantity injected and techniques used. Quality control measures must be 
used to insure that the grout is correctly mixed and properly injected 
into the required areas at the correct pressures and rates. Since the 
entire end results are underground, the degree of success cannot be known 
exactly until after the grouting is completed and some type of test or 
excavation is made in the grouted area. 

Control of the grout during the job involves constant monitoring of 
the grout components, injection pressures and quantity injected as a 
function of time. As a rule of thumb, the injection pressure should not 
exceed the pressure exerted by the weight of soil, which is equal to 
approximately one psi for each foot of the overburden. Excessive pressure 
in the soil will cause uplift of the ground above the point of injection 
by accumulation of lenses of grout, and damage to structures at the 
surface could result. Some means of checking the soil permeability before 
and after the grout treatment should be established. Soil strength should 
also be determined before and after grouting if it is possible to do so. 
Records should be kept during the entire field operation, showing all 
data pertaining to each phase of the job. 

Most of the European grouting companies use houses or vans with 
complete recording equipment for a permanent record of flow rates and 
pressures (see Figures 50, 51 and 52). Pumps are automated to pump only 
the preset volume of grout at each level of injection. Charts of flow 
rate and pressure are furnished by the grouting specialists to the owner 
as a part of his permanent file. The basis for the owner accepting the 
grouting as satisfactory is the similarity to past grouting performance. 
Where the grout system does not include recorders, accurate records should 
be kept to document the grouting and provide a basis for better evaluation 
of future grouting. 

P. Safety and Environmental Considerations 

Safety of the workmen is of prime importance. Visitors and neighbor- 
hood residents should also be included when considering safety measures. 

There are a number of problems that could be present when using 
chemical grouts. These include: 

1. Dust of the powdered chemicals which are 
toxic to the skin or when breathed. 

2. Fumes from the liquid mixtures for the grout. 

130 



3. Liquid mixtures of grout components which are 
toxic to skin. 

4. Contamination of groundwater by discoloration 
or poisoning. 

5. Mixing of chemicals in dry state rather than 
being dissolved in water, which can cause 
explosion. 

Protective clothing and gloves should be worn at all times, since 
most of the chemical grouts have some components which are toxic to the 
skin. Face masks should be available for workmen who must work in closed 
areas where fumes from grouts may be breathed. Protective headgear should 
be available for all workmen, as well as visitors at the site. Safety 
glasses should also be available for workmen and visitors in areas where 
grout is being injected to provide eye protection. 

Environmental impact should be considered before grouting is used. 
This is particularly true of chemical grouts which may be toxic and 
affect groundwater or impounded supplies of drinking water. The effect 
of the ground level uplift due to grouting with excessive pressures 
should be considered and limits of uplift established which would be 
satisfactory. Arrangements for disposal of excess grout should be made 
before the operation begins. 



131 



8. FIELD TESTS OF GROUTED SOILS 

A. Introduction 



Field testing of grouted soils is not common practice among the 
grouting specialists or construction companies. The usual procedure 
for checking results of grouting is to use safeguards during the 
actual grouting rather than make subsequent tests in the soil. For 
instance, surface structures are monitored for rise during grouting 
underneath the foundations, and grout is closely checked for quantity 
and injection pressure during the job. 

Some type of field test is needed, however, that would show if 
the grout permeated the soil as desired and provided the required 
strength. It would be helpful to the design engineers or owners if 
such tests could be related to unconfined compressive tests made on 
grouted soil samples before the grouting job. Knowledge of the 
grouting results before excavation could also prevent encountering 
unexpected trouble from water intrusion during construction. 

B. Current Practices 

In European underground construction, grouting is established as 
a dependable, efficient operation; the owners are satisfied that the 
guarantee by the contractor and the recorded data from grouting job 
substantiate the results. The contractors rely greatly on the injec- 
tion data and previous grouting experience for obtaining satisfactory 
results. In some instances for water stop grouting, some leakage 
after grouting is acceptable, so such criteria is established prior 
to the grouting. 

In the United States, contractors are usually told how much 
grout to inject; sometimes they are given a desired soil compres- 
sive strength to obtain after grouting, but there are usually no 
tests conducted to check results. When contractors make tests, 
they will probably use one of the following methods: 

1. Sampling and Laboratory Testing 

As previously indicated in Chapter 7, soil strength may be 
considered to be comprised of two components - cohesion c which 
reflects the shearing strength with no confinement, and internal 
friction represented by an angle $, which describes the additional 
strength resulting from confinement. Presently, the only widely 
accepted methods to evaluate these parameters involve sampling and 
laboratory triaxial or direct shear testing. 

Much attention has been directed towards obtaining relatively 
undisturbed samples of soft clay soils be means of hydraulically 
pushing any of a variety of sampling tubes. Simplest and most 

132 



common in the United States is the Shelby tube, which is essen- 
tially a sharpened thin-walled steel cylinder. Piston samplers re- 
present a modification in which a piston on top of the sample pulls 
a partial vacuum as the tube is pushed, thereby reducing accumulated 
side friction by pulling the sample into the tube. The Swedish foil 
sampler and the Dutch sampler, developed by the Delft Soil Mechanics 
Laboratory, further reduce side friction by simultaneously encasing 
the sample in unrolling foil or in nylon mesh, respectively, as the 
sampling progresses. These methods are available for sampling low- 
strength grouted soils, but they will probably be unsatisfactory for 
stronger soils or those containing gravel. 

Granular soils in their natural state present an even more dif- 
ficult sampling problem than clays, because sands compact during 
sampling and then fall apart when removed from the sampler. Further- 
more, gravel or coarser particles in the soil increase disturbance 
and may damage the sampler. A common expedient in the United States 
is the relatively thick-walled Gow or "split spoon" sampler used in 
a Standard Penetration Test (SPT) (ASTM D 1587-67). The sampler is 
driven by a 140 pound (63.5 kg) hammer falling 30 inches (76.2 cm), 
and the number of blows recorded for each 6 inches (15.24 cm) of 
penetration. Samples are used only for identifications, the rela- 
tive density being indicated by the blow count. In cohesionless 
soils a correlation has been obtained to friction angle $ and may be 
defended on the basis that both cf> and the blow count depend on rela- 
tive density, i.e., compactability. However, in grouted soils the 
pores should be filled solid, so the "relative density" is 100% - 
that is, the ideal grouted soil is not compactable. Furthermore, 
it usually has cohesion. Therefore, the SPT or similar less stan- 
dardized tests, such as drive cones, are useful mainly to detect 
extent of grouting, and not to evaluate strength of the grouted 
soil. Drive tests do have a function if there is doubt whether 
grout stayed where intended, or if it may have digressed through 
a thin, highly permeable layer or if it may have been washed out by 
flowing groundwater. 

Another means which would probably work well in grouted soil 
is to obtain a "core" using a mobile rotary drilling rig with a 
"core barrel." This core barrel is a hollow stem auger which is 
drilled into the soil by rotary action, trapping the soil within 
the barrel . 

The most positive means for obtaining a sample would be to 
sink or drill a large hole with supported walls, so that an in- 
dividual could be lowered from the surface to obtain a sample 
of the grouted soil . 

Any samples obtained through any of the above methods would 
then be laboratory tested for unconfined compressive strength. 



133 



2. Permeability Testing 

A method sometimes employed is the measurement of in situ perme- 
ability reduction obtained by the grouting. This test should be con- 
ducted before the grouting as outlined in Chapter 4, Section B, of 
this report, using either constant head or falling head test, and 
then repeated after grouting. The comparison will indicate the ef- 
fectiveness of the grouting. A reduction of permeability from an 
initial value of 10 _1 cm/sec or greater to a final value of 10" 5 
cm/sec or less might be ample for water shutoff and even possibly 
for strengthening. A decrease in permeability gives an indication 
of strength increase. 

3. In Situ Strength Tests 

The difficulty in sampling grouted soils indicates a greater 
reliance on in situ tests. The four most common methods recently 
listed by Schmertmann (50) are the previously mentioned SPT, the 
Menard pressuremeter, Dutch (static) cone test, and vane shear 
test. A fifth method believed to hold sufficient promise is the 
Iowa Borehole Shear Test (BST). Of these, only the pressuremeter 
and BST appear to be applicable to grouted soils. 

a. Pressuremeter . The pressuremeter test involves inflating 
a rubber membrane inside a borehole and measuring the volume ex- 
pansion as a function of applied fluid pressure (44). The test can 
be performed in a standard EX, AX or NX borehole. This equipment, 
shown schematically in Figure 70, consists of a combination volumeter- 
manometer connected to a cylindrical borehole expansion device. This 
probe is constructed of a steel tube surrounded by two flexible rub- 
ber membranes, the interior membrane forming the measuring cell and 
the exterior membrane providing the guard cells at the two ends of 
the probe (45). The guard cell is activated by gas pressure and is 
used to reduce end effects on the measuring cell to provide an essen- 
tially two-dimensional condition. The measuring cell is pressurized 
with water which is kept at a slightly higher pressure than the guard 
cell to insure that it is always pressing against the borehole wall. 
Two concentric tubes connect the volumeter to the probe. An adapter 
connects the probe to a standard drill rod for lowering and raising 
the probe within the borehole. 

After lowering the probe to the desired depth, pressure is ap- 
plied to the borehole wall by inflating the rubber membranes. The 
volumeter-manometer accurately measures the radial expansion under 
each pressure increment. Testing can be performed swiftly and eco- 
nomically during the drilling operation. During the early part of 
the test the soil is assumed to behave elastically. In soils, 
further expansion initiates plastic shear failure, which starts 
when applied pressure equals the original horizontal pressure plus 
the soil cohesion. 

134 



Pressure gage 



-0 



Gas line - 



Concentric tubing . 



^mxm 



Zone of core 
hole under stress 



If 



% 



X- II 



JJ 



^. 



Relief 
valve 



Pressure _ 
volumeter 




Compressed gas 



-Manometer 



Water 
— .4 r , . mLji \—fo / 



n|t" 



1 

§ 



Exterior guard cell 

Zone of core hole 
under measurement 



-Interior measuring cell 



Core hole expansion device (probe) 



Figure 70. Schematic drawing of pressuremeter equipment (45) 

A typical pressuremeter test result is shown in Figure 71. 
The beginning pressure (P Q ) and end pressure (P f ) of the elastic 
stress range, and the limit or failure pressure (Pg) are indicated. 
The P value approximates the at-rest pressure. 

400 



£ 300 



200 



> 100 







Pressure meter test 


















£ r «2 772 ksf (rebound) 


















o 




















































1 
1 
| 




































































\P„ 








ll 










\ P l 



10 20 30 40 50 60 

Corrected pressure, in kips per square foot 

Figure 71. Typical results of a pressuremeter (45) 

135 



The interpretation of pressuremeter data involves evaluating the 
in situ horizontal stress P from the data plot, and then evaluating 
either cohesion c assuming <|> = 0, or friction angle <f> assuming c = 0. 
Cohesion may be obtained from a semi -empirical equation 

%_ = c u = p £ - P (73) 



5.5 



where 



q = unconfined compressive strength 

c = undrained cohesion 
u 

P^ = limit (maximum pressure) of pressuremeter 

P Q = in situ horizontal stress of soil 

P Q is roughly determined from the pressure-volume curve, and strongly 
influences the calculation of c u . Correlations to data from other 
tests are somewhat erratic, the pressurementer c u usually being too 
high and thus on the unsafe side for design. Sensitivity to hole 
disturbance recently led to introduction of self-boring pressure- 
meters (51), but the latter probably could not be used with grouted 
soils because cuttings must be carried up through the core of the 
instrument. 

The evaluation of <f> from pressuremeter data has been even more 
challenging, in part because of strong dependence on horizontal 
stress. One method is to assume various horizontal stresses and by 
trial -and-error solution evaluate the minimum d> ( 52 ) . The appropriate 
equations are 



P- = P (1 + sin 4>)(I r sec <j)) sin * n + sin * 



where 



I 

(74) 
rigidity index I p = 2 (1 + Vl Mc u + P Q tan <(,) 

and Vi = Poisson's ratio 

E = Pressuremeter modulus 



2v (1 + Vl ) 

AV 



AP 
AV 

v = initial volume 

AP/Av = slope of the pressure-volume curve 

c = cohesion 
136 



A computor is needed for solution, and cohesion should be inde- 
pendently measured or assumed to be zero. 

Most grouted soils have considerable internal friction as well 
as cohesion. Thus at its present stage of development the pressure- 
meter may be used to estimate one or the other (usually c), but not 
both. A major problem appears to be dependence of the data on ini- 
tial in situ stress, which is changed by grouting. Furthermore, 
tensile failure of the grouted soil may mask the already weak deter- 
mination of P . 

This test was used in Washington, D. C. on a large grouting job 
performed for the purpose of strengthening the material under highway 
1-95 at 7th Street. The soil materials were sediments with some re- 
latively large gravel particles in them. When the membrane was 
inflated, apparently single point contact pressures were obtained on 
these particles; the membrane was ruptured, so that no meaningful 
readings were obtained. However, this tool has been demonstrated 
under adverse conditions using the elements inside of split casing. 
This permits the casing to expand under the pressure of the rubber 
packers without significant resistance, and it protects the tool 
from sharp gravel in the soil. 

b. Borehole Shear Test . The borehole shear device developed 
at Iowa State University involves expanding opposed serrated plates 
to engage soil in opposite sides of a smooth borehole, and then 
pulling to induce shear in the soil. The expanding shear head is 
shown in Figure 72. Both the expansion and pulling forces are 
monitored. The nominal normal and shearing stresses, a n and t, 
are obtained by dividing the measured forces by appropriate plate 
areas. A plot of maximum shearing stress versus applied normal 
stress gives a Mohr-Coulomb type linear failure envelope with slope 
<f> and ordinate intercept c. The test is essentially a drained test 
except in saturated heavy clays, where it may be undrained. It can 
be performed in any sand or clay soil with or without drilling mud 
to hold the hole open (70) . 

Limitations of the BST are: 

1. If gravel content exceeds about 10% it may be 
impossible to secure a smooth hole. 

2 

2. Cohesion exceeding about 10 psi (0.703 kgs/cm ) 
will keep the plate teeth from seating. In this 
case <J) will be too high and c too low (usually 
zero), but the envelope will remain below the 
true failure envelope and is thus on the safe side. 



3. Drainage conditions are inferred from the data 
and by retesting with different consolidation 
times. 

137 



7-x 2A 



^ 



o n xA 



^ 



A 



Figure 72. Borehole shear device (32) . 
Advantages of the BST are: 

1. It is the most rapid method available for 
independent evaluation of c and <j> , a complete 
test usually requiring 30 minutes. 

2. Data are reduced and plotted while the test 
is being conducted, enabling immediate value 
judgements and retesting if necessary. 

3. Its use is not limited to either clays or sands; 
it tests either alone or both combined in mix- 
tures. 

4. It is not sensitive to hole disturbance provided 
the drained, sheared soil has higher strength 
than the undisturbed soil and therefore adheres 
to the shear plates. Successive tests at higher 
normal stresses are performed without relocating 
the instrument, a technique known as stage testing, 

138 



The major limitation of the BST for grouted soils is that a 
moderate cohesion will prevent plate seating. However, the bore- 
hole shear principle recently has been extended to development of 
a rock borehole shear 2 tester (RBST), enabling cohesions exceeding 
1000 psi (70.3 kgs/cm ) to be measured. In this case stage testing 
is not used, the instrument being removed from the hole, cleaned 
and rotated for successive failure points. However, rocks such as 
coal and shale that are too soft to sample are successfully tested, 
avoiding the problem of bias toward the unsafe side due to recovery 
and testing of only the strongest cores. Siltstone, sandstone, 
limestone and concrete also may be tested, the limitation being 
that shearing stress cannot exceed 7000 psi (492 kgs/cm 2 ), corres- 
ponding to an unconfined compressive strength in excess of 14,000 
psi (984 kgs/cm 2 ). The instrument is being developed at Iowa 
State University for the U. S. Bureau of Mines. 

c. Goodman Jack . The Goodman Jack is another tool used in 
evaluating or measuring rock properties. One model is designed for 
soft rock. This tool is a hydraulic jack with curved bearing plates 
for use in a 3-inch (76.2 mm) diameter borehole. The plates are 
forced against the wall of the borehole by hydraulic pistons, and 
the borehole deformation is measured accurately by two self-contained 
Linear Variable Differential Transformers (53). 

This tool could possibly be used to measure the strength of 
grouted soil. Field trials should be conducted. 

The tool for soft rock and the indicator used with the tool 
are shown in Figure 73. 




Figure 73. Goodman jack for borehole testing soft rock model 

139 



4. Relation of Test Information to Unconfined 
Compressive Strength 

Most concrete or rock cores are tested in unconfined com- 
pression, the maximum axial load divided by the cross-sectional 
area being the unconfined compressive strength, q u . If the fric- 
tion angled is zero, it may be shown that q u = 2 c, c being 
cohesion. In most instances <j> is not zero, and there is fric- 
tional resistance along the failure plane, which is inclined. 
For uniform confinement effects from end friction, the minimum 
height-to-diameter ratio for a valid test is usually standardized 
at 2.0. The theoretical shear plane inclination (Figure 43 (e)) 
in a vertical load test is 45° +<j>/2 with horizontal, soc^may be 
estimated by measuring the failure angle. The relations between 
q u , <f> and c are as follows: 

2 c cos d) , „_ » 
% = 1 - sin I = 2c cot ( 45 " 1 ) (76) 

q 

q.. (1 - sin " tan (45 - $ ) (77) 

C = — — ~~0 ~0 

2 cos (J) * L 

Although the unconfined compressive strength greatly underes- 
timates reliable design strength when the soil is confined, it is 
useful for predicting stability of unsupported tunnel walls or 
excavations. 

Example 1 : A 4-inch diameter core 8 inches long is loaded axially 
to failure which occurs when the load is 9000 lb. The break angle 
is measured and found to be 55°. Find q u , c and <j> . 

Solution: 

a) q u = 9000 lb -f tt (2 in) 2 = 716 psi 

b) 55° = 45° + <j)/2 

<f> = 20° 

c) c = ™ tan (45-10) = 251 psi (Using Equation 77) 

Example 2: A RBST gives c = 1500 psi and <J> = 32°. Estimate q 
and the maximum depth for an unsupported tunnel wall with stress 
concentration of 2 and an additional factor of safety of 2. 

Solution: 

a) q = 2 (1500) cot (45 - 16) (Using Equation 76) 

= 5410 psi = 779,000 psf 
140 



b) Assuming the overburden density y is 150 pcf, 

h 779,000 , 150h 
2x2 



h = 1300 ft, 



(This does not preclude buckling failure of walls, which would be 
analyzed as thin columns.) 

5. Performance Evaluation 

Satisfactory performance of the treated soil deposit and/or 
the protected structure under stress is the most important crite- 
rion of a successful treatment. The most common way of evaluating 
the grout treatment is to proceed cautiously with construction and 
observe carefully for any signs of failure or grout deficiency. 

Adequate performance of the grouted soil is the ultimate test 
as to the value of the grouting, and many times this is the only 
criterion used. When the grouted soil does not perform as expected, 
the additional remedial work is likely to be wery costly and time 
consuming. Performance methods can be risky, especially for strength 
grouting. The consequences of ineffective grouting might be irre- 
pairable. 

C. New Concepts 

Improved methods for evaluating the adequacy of the grout treat- 
ment are needed; in particular, field methods are desired that can 
be conducted in place. Samples for controlled laboratory testing 
are difficult to obtain, and facilities for testing are not always 
available. 

Two problems which must be solved for evaluation of grouting 
success prior to performance are (a) is there proper distribution 
of the grout in the soil? and (b) have the pertinent soil proper- 
ties been obtained? As indicated above, progress is being made on 
the latter problem by measurement of soil properties in situ; both 
the pressuremeter and borehole shear techniques appear promising 
for strength evaluations. On the other hand, indirect determination 
of the distribution of grout in soil has had only moderate attention. 

Two types of geophysical tests are available and commonly used 
for remote determination of soil changes with depth; these are seis- 
mic refraction and electrical resistivity. The resistivity methods 
are more sensitive to changes in soil pore fluid, and thus could be 
used to monitor distribution during grouting. The seismic methods 
are more responsive to changes in soil strength and elasticity, and 
thus should perform well after grouting. The seismic refraction 
methods have a disadvantage in not penetrating below a hard layer; 

141 



thus the depth to the top of a grouted formation might be deter- 
mined. 

The feasibility of using resistivity measurements to determine 
the progress of grouting has been confirmed in small-scale labora- 
tory tests which show a marked change in soil resistivity upon 
grouting. The information and data on these tests are included in 
Section D-2 of the Appendix. Further development of the necessary 
hardware and testing in full scale field operations is recommended. 



142 



9. SLURRY TRENCH AND DIAPHRAGM WALL CONSTRUCTION 



A slurry trench is generally defined, in the United States, as 
a narrow trench, excavated under a bentonite slurry and later back- 
filled with spoils or selected materials, from clays to gravels (55). 
The slurry trench provides a temporary barrier to the movement of 
water through the soil. The bentonite slurry exerts a hydrostatic 
force against the walls of the trench in excess of the groundwater 
pressure, thus providing temporary support for the vertical trench 
walls. 

The bentonite used in the slurry is an ultrafine clay, of which 
the principal mineral constituent is sodium montmorillonite. The 
slurry is a colloidal suspension of bentonite in water, with thixo- 
tropic properties forming a gel structure of sufficient consistency 
to hold large particles in suspension. A "filter cake" of tightly 
packed bentonite molecules is formed on the wall of the excavated 
trench or hole as the slurry tends to permeate the adjacent soil. 
This cake then acts as a water-tight membrane to maintain the dif- 
ferential pressure at the interface. 

A slurry wall (called a diaphragm wall in Europe) is essen- 
tially a slurry trench excavated under bentonite slurry and back- 
filled with concrete and steel reinforcement. The concrete 
displaces the bentonite slurry to form a concrete wall. A dia- 
phragm wall is sometimes constructed using precast concrete elements 
placed in a slurry trench. In this construction, cement is added to 
the bentonite slurry so that the slurry provides a seal at the sec- 
tion joints of the precast elements. 

Slurry walls were first constructed in Italy in 1948 when pa- 
tents were obtained by I.C.O.S. of Milan, Italy. This system was 
used in other European countries by 1954, and applications were made 
on most continents by 1962, when it reached the United States. The 
technology has improved so rapidly that technical solutions which 
could not be forseen 25 years ago are commonplace today. 

The purpose of the diaphragm wall is to provide rigid walls 
for supporting the sides of excavated sections of earth. Dia- 
phragm walls are more rigid than sheet pile walls or soldier beam 
and lagging walls. They can be built in a variety of sizes and 
shapes. Work can be performed adjacent to existing buildings with- 
out disturbing their foundation support. This method minimizes 
disruption to traffic in urban areas and reduces the need to re- 
locate and resupport utilities; it also eliminates noisy driving 
equipment necessary for piling. 

A. Current Practices 



The design and construction of slurry trenches and diaphragm 

143 



walls has grown into a science; the use of this type of construction 
has spread throughout Europe and is becoming more common in the 
United States. Diaphragm walls are being used to support the ground 
adjacent to excavation, and in the construction of many European metro 
systems. The reinforced concrete walls range in thickness from 18 
inches to 60 inches; they are cast in sections not exceeding 25 feet 
in length. 

Several methods are used for constructing diaphragm walls. The 
most common method employs a clamshell bucket to excavate a narrow 
trench in sections around the desired area. The alignment of the 
trench is controlled by two concrete guide walls on either side of 
the trench. These guide walls and the special, narrow clamshell 
bucket hanging from the weighted arm of a large crane can be seen 
in Figure 74, a Metro system job in France. These clamshells can 
be hydraulically or mechanically operated, and the bucket is either 
cable-suspended or controlled with a kelly bar. 







Figure 74. Clamshell bucket crane used for slurry trench construction 

144 



As the trench is dug, bentonite slurry is pumped into the 
trench to replace the excavated material. The level of the ben- 
tonite slurry must be maintained at least 2 feet (61 cm) higher 
than the highest level of ground water, and the weight of the 
slurry must be kept consistently greater than that of the ground- 
water to insure a positive static pressure on the walls of the ex- 
cavation. The slurry is often circulated back to a desanding plant 
during excavation to control the slurry weight; suspended particles 
are removed as the slurry passes over a screen in the system. 

Several methods are used to construct a diaphragm wall. These 
include: (1) steel beam and cast concrete panel, (2) jointed-end 
panels, and (3) precast concrete panels. 

1. Steel Beam and Concrete Panel Wall 

After the slurry trench (or a portion thereof) is finished, 
wide flange steel beams of sufficient width to fit across the 
trench are installed at selected intervals to form panel joints 
as shown in Figure 75. 

A prefabricated cage of reinforcing steel is placed in the 
panel section. Concrete is then placed by the tremie method to 
displace the bentonite slurry. Figure 75 shows a completed con- 
crete wall panel, a panel being constructed, and a section of 
slurry trench excavation (56). 



Benlonile 
Slurry Line • 




Figure 75. Slurry trench and diaphragm wall construction (56) 

145 



Jointed-End Panels 



In this type of construction, a large pipe is placed at each 
end of the initial wall section to form a concave joint at each end. 
In subsequent sections, a pipe is only needed at one end. 

When the concrete is placed and begins to set, the end pipes 
are slowly withdrawn to form a semicircular joint at each end of 
the panel. This approach has been modified by Soletanche Entre- 
prises of France as shown in Figure 76 to provide a more impervious 
joint. Single or double key joints are placed in line with the 
panel joint, then removed before concrete sets to form a vertical 
cavity. When the concrete hardens sufficiently, the joint can be 
grouted through the cavity. A water-stop joint can also be used 
in lieu of key- tube and grouting (57). 



Single key joint 



joint-tube 



key-tube 




1 - Concreting of 
primary panel 



2 - Concreting of 
secondary panel 



Concreting of 
single key 



Double key joint 



key-tube 



joint -tube 



7 - Concreting of 
primary panel 



double key-tube 




2 - Concreting of 
secondary panel 



3 - Concreting of 
double key 



Water-stop joint 



joint-lube 




water -stop 

1 ■ Concreting of 
primary panel 



2 - Drilling of 

secondary panel 

and clearing of water-stop 



3 - Concreting of 
secondary panel 



Figure 76. Alternate methods for sealing diaphragm wall panels (57) 

3. Precast Concrete Panels 

Another type of construction for diaphragm walls using slurry 
trenches is the use of precast concrete wall panels. These panels 
are placed in the slurry trench and fitted together to form the 
wall. A number of distinct advantages are claimed over the cast- 
in-situ-type wall (58). These are: 

a. The general apperance is superior. No cutting 
back of irregular wall surface is required and 
the finished surface is even and clean. 



146 



b. The shape of the diaphragm can be tailored to 
form an integral part of the final structure, 
satisfying technical and economic considerations. 

c. Improved concrete quality and accuracy in placing 
reinforcement give considerable savings on mate- 
rials; prefabricated diaphragms are generally 30% 
thinner than cast-in-place designs. 

d. The prefabricated diaphragm can be built and in- 
stalled in the ground to finer tolerances, and wall 
openings can be more accurately positioned. 

e. Watertightness at the joints and in the wall itself 
is better than with conventional diaphragm walls. 

The Prefasif system, developed by the Entreprise Bachy of Paris, 
France, uses panels about 2 meters (6.56 ft.) wide; these are locked 
together by a special device at the lower end which lines them up 
with adjacent panels. A double female joint left between panels is 
subsequently regrouted, with a waterstop inserted if desired. The 
bentonite slurry is replaced with a sealing grout just prior to 
insertions of the precast Prefasif panels. 

A similar system, called Panosol , was developed by Soletanche 
Entreprise of Paris. This system has a tongue and groove type 
joint to line up the panels. It is also available with T-beam 
joints between wall sections. The seal between the panels is ob- 
tained from special slurry remaining in the trench. A slurry of 
bentonite and cement is used during excavation of the trench, and 
that portion not displaced by the wall sections is left in the 
trench to harden. The grout fills any voids in the joint between 
adjoining panels, and between the precast wall and the soil. 

4. Other Excavation Methods 



Another type of trenching machine used for digging slurry 
trenches is the special trenching machine developed by E.L.S.E. 
in Italy in 1958. This machine consists of a trenching shovel 
traveling on a mobile vertical mast which runs on a fixed mast at 
the forward end of a large structural frame. The bare frame moves 
on rails laid on the ground and operates by electrically powered 
winches. 

Two other methods are sometimes used. One method performs 
excavation with percussion tools. This technique is used in 
very hard soil which might be strewn with boulders; the excava- 
tion starts by drilling primary holes with bentonite slurry and 
then concreting by the tremie method. Then a tool is used to chop 
out the area between the concreted holes. This method is slow and 
more expensive than the clamshell method; however, it is the only 

147 



method which can be used for trenches to depths in excess of 200 feet 
(61 m). The other method involves drilling a series of holes at 
short intervals, then excavating the material between the holes using 
some type of a clamshell rig. 

B. Engineering Characteristics of Trench Slurry 

The use of bentonite slurry in the drilling of oil wells has 
been standard procedure for many years. There has been much re- 
search on this technique to develop materials for use under the 
extreme temperatures and pressure requirements of deep drilling. 
Companies exist in the petroleum service area whose sole business 
is manufacturing and supplying the materials, and supervising 
their mixing and applications. This is possible because the quan- 
tities used are so large, and the use is so critical. However, 
the requirements for slurry trench construction are much less 
exacting because the use is at ambient temperatures and normally at 
depths less than 200 feet (61 m). It is necessary that the bento- 
nite slurry used in trenches and drilled holes accomplish the fol- 
lowing (59): 

a. Support the excavation by exerting hydro- 
static pressure on its walls, 

b. remain in the excavation, and not flow 
into the soil , and 

c. suspend detritus to avoid sludgy layers 
building up at the excavation base. 

In addition, these slurries must allow for 

d. clean displacement by concrete, with no 
subsequent interference with the bond 
between reinforcement and set concrete, 

e. screening or hydrocycloning to remove 
detritus and enable recycling, and 

f. easy pumping. 

The most important properties of bentonite for use in the 
slurry trenches are defined in Tables 10 and 11. 

Tests have shown (59) that the bentonite concentration 
should be over 4-1/2% to obtain low fluid loss for proper sup- 
port of the excavation and proper sealing of the wall. This 
would be a good rule to observe in the use of bentonite for 
slurry trenches. 



148 



T 


able 10. Bentonite Slurry 


Properties 


Property 


Definition 


Current Test Method 


Concentration 


Kg of bentonite per 
100 kg water 


— 


Density 


Mass of given volume 
of slurry 


Mud balance (e.g. 
by Baroid 



Plastic 

Viscosity 
Apparent 

Viscosity 
Yield Stress 



For a slurry (behaving 
as a Bingham body) under 
shearing conditions: 
Shear stress = T + V S 
where 

T = yield stress 
V p = plastic viscosity 
S = shear rate 
Apparent viscosity = 
shear stress/shear rate 
and is dependent upon 
shear rate for a Bingham 
body 



Fann Viscometer 



Marsh Cone 
Viscosity 



Time for fixed volume of 
slurry to drain from a 
standard cone 



Standard Marsh cone 
as used by drilling 
companies 



10-Minute 
Gel Strength 



Shear strength attained Fann Viscometer 
by the slurry after Falling tube shear- 
quiescient period of 10 ometer. (Note: 
minutes. (Slurry violently these two measurements 
sheared before give answers which 

starting) commonly differ by up 

to a factor of 2. 



PH 



Logarithm of the recip- 
rocal of the hydrogen 
ion concentration 



pH meter, pH papers 
can give unreliable 
results 



Sand Content 



Percentage of sand 
greater than 200 mesh 
in suspension 



API sand content test 
(basically 200 mesh 
screen) 



Fluid Loss 



Volume of fluid lost in 
set time of slurry when 
filtered at set pressure 
through standard filter 
medium 



Standard fluid loss 
apparatus as used by 
drilling companies - 
(600 cm mud, 100 lb/in 2 
30 min. filter paper) 



Filter Cake Thickness of filter cake 
Thickness built up under standard 
conditions. 



Measure filter cake 
buildup in fluid loss 
test 



149 






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The fluid loss (or filtration) and wall-building characteris- 
tics of the slurry are measured by means of a filter press using 
the standard API (American Petroleum Institute) 30-minute test. 
These filter presses are standard, and are available from Fann In- 
strument Corporation, Houston, Texas or from one of the oil field 
mud companies. 



The initial 
tant. Benton ite 
plete hydration a 
higher final shea 
stirrer. This is 
the degree of hyd 
slurry. This can 
slurry is mixed, 
centrations of be 



mixing of the water and bentonite is very impor- 
prepared with a high shear mixer has more com- 
nd a much faster rate of hydration, as well as a 
r strength, than that prepared with an anchor 
shown graphically in Figure 77. A measure of 
ration is the 10-minute gel strength of the 
be measured with a Fann viscometer when the 
Figure 78 shows gel strength for various con- 
ntonite (60) 



Viscosity can be measured during excavation with a Marsh fun- 
nel to determine the need for adding either water or bentonite 
to the slurry. The density can be measured using a standard 
mud balance. 



CVJ 

E 
u 

c 
>» 

TJ 

X 

o 

z 

UJ 

cr 

H 
05 



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o 

z 
5 




MIXER 



RRER 



200 400 600 800 1000 1200 1400 
TIME AFTER MIXING: MIN 



Figure 77. Effect of mixing on hydration of slurry (5% bentonite) (59) 

151 




Parts of clay per 100 parts water. 

Figure 78. Gel strength for bentonite (60). 

C. Specification and Cost Data 

A sample specification for diaphragm walls has been published 
by one of the large European foundation companies. This specifica- 
tion is included in Section E of the Appendix. 

The cost of a slurry wall is very dependent on local condi- 
tions, such as the soil profile, the labor market and the degree 
of urbanization at the site; but cost is less dependent on wall 
thickness and the quantity of reinforcing steel required. The 
local conditions must be carefully analyzed from job to job. 

The costs in the following paragraph were developed by Tamaro 
in a 1970 paper (55). Allowance should be made for cost increases 
since 1970. 

A 70 foot (21.34 m) deep wall, 30 inches (76.2 cm) thick and 
containing 15 pounds per square foot (73.23 kgs/sq m) of reinforcing 

152 



steel, can be constructed in granular or cohesive soils, without ob- 
structions, using clamshell equipment at a cost between $10.00 and 
$20.00 per square foot. The same wall, constructed in a formation 
of till, boulder strata or weathered rock requiring percussion equip- 
ment would cost between $30.00 and $50.00 per square foot. A pre- 
mium of 10% of the base cost should be added for each 50 feet 
(15.24 m) of additional depth below the initial 70 feet (21.34 m) 
of depth. 



153 



10. CONTRACT DOCUMENTS AND SPECIFICATIONS 



One area of particular interest and concern to grouting contrac- 
tors is the contractural arrangement for construction work. There is 
a marked difference between practices in the United States and in 
Europe; this difference was pointed out in interviews with contrac- 
tors in both countries and in a recent study of contracting for under- 
ground construction for the National Science Foundation (61). 

A. Current United States Contracting Practices 

Public agencies, both federal and state, and private owners al- 
most invariably issue contract documents that include detailed plans 
and specifications, often prepared by engineering organizations. Pub- 
lic agencies usually issue these to all contractors who express an 
interest in the job as a result of public notices. In the private 
sector, however, bidders are usually prequalified. Their qualifica- 
tions to perform the work are investigated and approved before the 
bidding documents are issued to them. 

The plans and specifications are prepared either by engineers 
directly employed by the owner (normally the situation with public 
agencies engaged in a substantial and continuing program of con- 
struction), or by an engineering organization engaged by the owner 
for this purpose. The owner's staff engineers or the engineering 
organization will arrange for subsurface investigations, analysis 
of the results, and preparation of designs, plans and specifica- 
tions, cost estimates, and performance-time schedules for construc- 
tion. Staff engineers or separate engineering organizations will 
be employed to perform management and administrative functions on 
behalf of owner. These tasks will be in connection with construc- 
tion performance and the evaluation and determination of the validity 
of contractor claims for additional money or time for performance. 

In the invitation to bid, notification is given of the form of 
contract that will be awarded; this is usually a firm-fixed-price 
contract. Technical plans or drawings and contract documents are 
included. 

Public agencies will require that sealed bids be submitted, 
accompanied by a bid bond or cash deposit to guarantee execution 
of the contract documents by the successful bidder. In the pri- 
vate sector, however, bid bonds are seldom required. 

All bids are publicly opened by public agencies at the time 
and date specified in the invitation. At that time, bid prices 
are announced with the engineer's estimate, and the bids are im- 
mediately made available for inspection by the public. Private 
owners very seldom open bids publicly, publish the engineer's 
estimate, or make bids available for public inspection. 

154 



All public agencies and most private owners require that the bid 
be responsive to the invitation, i.e., that it must not be qualified 
or restricted concerning quality, quantity, price, or time for perfor- 
mance of the work. After bid opening, the lower bidder must satisfy 
the owner, if he has not already done so, that he is responsible. 
This means that he has a satisfactory record of performance of like 
work, and the management capability, financial strength, and equipment 
availability to assure timly performance of the job as specified. 

Award by public agencies is made to that responsible bidder who 
submits the lowest responsive bid. Private owners are not bound by 
any such legal requirements concerning acceptability of bids. 

On award of public agency contract, the contractor must furnish 
performance and payment bonds in the amounts called for in the invi- 
tation to bid. Private owners will normally make no such requirement 
if they have prequalified and preselected bidders for invitation to 
bid. 

B. Current European Contracting Practices 

In European countries, contracting practices vary from one 
country to another and even within a country. To some extent, 
however, certain practices prevail within all countries. 

Consulting engineers are used in England in the same manner as 
in the United States, i.e., in the planning of projects and in pre- 
paration of contract documents. In other European countries, the 
owners normally prepare drawings and specifications and supervise 
the construction with their own engineering staff. 

Potential contractors are prequalified, i.e., the qualifica- 
tions and experience of their management personnel, their finan- 
cial capacity, equipment availability, and their past record of 
work performance and claims submissions are investigated. Owners 
are particularly interested in a potential contractor's past re- 
cord of arbitration and court litigation. Contractors found to 
have satisfactory records in these areas are then placed on a list 
of qualified bidders. 

Contractors are preselected for invitation to bid by a two- 
step procedure. First, they are placed on a prequalified list. 
Second, a specific number of contractors are selected from the 
list to receive an invitation to bid; however, all on the list 
may be invited. 

Bidders are, in general, permitted and even invited to sub- 
mit an alternative design for the job, provided that they fulfill 
the following requirements: 

(1.) A bid is submitted for performance of the job 

155 



as advertised, so that the owner will have a 
comparable basis for evaluating all bid re- 
ceived. 

(2.) Any alternative proposed must be accompanied 
by detailed plans and specifications, together 
with the bidder's written justification for 
adoption of the alternative. The bidder 
must also include a bid price schedule cover- 
ing the alternative submitted, and must be 
prepared to support his prices for an alter- 
native with his detailed cost estimate. 

Although the attachment of qualifications and restrictions on 
the bid is discouraged and may be prohibited by the owner, contrac- 
tors are, as a practical matter, allowed to attach such qualifica- 
tions on the bid which affect one or more of the following factors: 
quality, quantity, price, or time of performance. Although the owner 
has the option of rejecting any qualified bid, he will negotiate with 
such a bidder and with others whose bids are close to the estimate. 
Following such negotiations he will award the contract on the basis 
of the best price for the job as modified by an alternatives and qua- 
lifications that he has accepted. 

Bids are, in general, opened privately, and negotiations may 
then be conducted with the apparent low bidder and with other close 
bidders, covering bid prices, alternatives, and qualifications on 
bids. This particular procedure represents a radical difference 
from contracting practice in the United States, except for jobs 
awarded by some private owners. 

Contractors are reluctant to resort to arbitration and es- 
pecially to court litigation, because this usually results in their 
removal from the list of qualified contractors. In any event, the 
contractor who resorts to such means for collecting on claims ac- 
quires the reputation of being a "hard head". 

In one of the countries visited, subsurface conditions are 
generally thoroughly investigated by owners. The results of 
this investigation, including interpretations of the basic data, 
are furnished to bidders more frequently than they are in the 
United States. The practice varies greatly, however, from country 
to country and even within a country. Owners generally assume the 
risk concerning changed subsurface conditions. 

C. Contractural Problems with Grouting Contractors 

For the United States, the grouting contractor is generally a 
subcontractor to the general contractor, often for a fixed fee. 
Since the general contractor is usually awarded a firm-fixed-price 
contract, he essentially becomes the owner of the project until it 
is completed and delivered to the ultimate owner. For that reason, 

156 



the public agency contracting officer or private owner will deal 
only with the general contractor. The grouting contractor, work- 
ing under the general contractor, does not usually have anyone 
who is interested in his work or its success. If he decides to 
make changes in his grouting program (which are necessary many 
times due to unexpected conditions encountered), the general con- 
tractor will not adjust his contract to permit any changes result- 
ing in additional charges. This poses a difficult problem for the 
grouting contractor who must redesign his grouting program during 
the course of the job, and possibly not be paid for additional 
costs encountered. 

There are times when ground conditions with flowing water 
and/or running sand are encountered which halt normal construc- 
tion progress. This unforseen development is not covered by a 
fixed-price contract, so the general contractor must seek appro- 
val for additional funds to complete the job without losing money. 
This proves difficult, but the contractor is reluctant to proceed 
without this approval. As a consequence, many jobs are delayed 
while arbitration and litigation take place. 

Sometimes the general contractor will employ a grouting con- 
tractor for a trial grouting operation, but the scope is usually 
insufficient to accomplish a satisfactory solution or prove the 
feasibility of such approach. However, this gives the general 
contractor better grounds to obtain additional funds for changed 
site conditions and obtain relief from his fixed-price contract. 

Meanwhile, the grouting contractor is not free to negotiate 
a contract for a procedure which would probably alleviate the 
problem. This is one factor that has kept grouting from becoming 
a useful technology in underground construction practices. 

In Europe, this situation does not normally exist. On many 
of the European Metro systems, their engineers design the system 
and include grouting as part of the original contract. In such 
cases, negotiations are made directly with the grouting company. 
Moreover, when grouting work is indicated in underground construc- 
tion because of problems encountered, the Metro system personnel 
still deal directly with the grouting contractor. This procedure 
provides a more responsive situation than exists in the United 
States. 

Owners and contractors appear to work more as a team in Europe 
than they do in the United States. They are both reluctant to 
force a dispute to resolution by arbitration, and contractors who 
propose alternatives have an incentive to make them work. The 
owners who accept the alternatives also have a concern in the 
success of such work. Mutual interest is a key in successful 
relationships. 

157 



11. SUMMARY AND EVALUATION 



General systems analyses of the entire grouting operation, pri- 
marily in cohesionless soils, have shown that there are some distinct 
differences in grouting performed in the United States and that per- 
formed in Europe. These differences seem most pronounced in the 
size of the jobs, the basic injection techniques, the pumping and 
mixing equipment, the site investigation and contractual arrange- 
ments. 

In the United States, most of the jobs are small and are per- 
formed on an emergency basis. Grout is normally injected through 
open end or slotted pipe into all the layers adjacent that will ac- 
cept the grout. Many times one pump is used to inject the grout 
into a number of pipes simultaneously. The site investigation has 
already been performed without consideration for grouting, so infor- 
mation often is meager. 

In European operations, many of the jobs involve grouting large 
sections of Metro systems as a part of the original planning. Grout 
is injected selectively into one layer at a time using the tube a 
manchette pipe system. Pumping and mixing equipment are in batte- 
ries of six to eight units, housed in a small shed or trailer, and 
automated so that each pump injects grout into one pipe and shuts 
off automatically at the proper volume. These companies perform 
their own site investigation in many instances. 

The various aspects of soil grouting in cut-and-cover or soft 
ground tunneling have been discussed in preceeding sections of the 
report. However, each aspect relating to tunneling will be examined 
again for the purpose of determining the needs for, the consequences 
of, and the prospects for improvements. The areas to be examined 
will be: (1) grout curtains for cut-and-cover; (2) waterstop bar- 
riers for cut-and-cover or tunnels; (3) remedial grouting; (4) 
strengthening soil under structures above tunnels; (5) consolidating 
soil for tunnel excavation; (6) slurry trenches and diaphragm walls; 
and (7) backpacking tunnel liners. 

Table 12 gives information on the seven areas listed above. In- 
cluded are the materials required, the grouting procedure, the moni- 
toring required during grouting, the testing necessary after grouting, 
and the results of each type of grouting. 

Table 13 shows the need for improvement, the consequences of 
improvement, the prospects for improvement and the approaches to im- 
provement for the seven areas of grouting. 

Equipment is badly needed to monitor the distribution of the 
grout throughout the soil during injection. Such equipment could 
be used to optimize the use of grout and materially reduce the cost 

158 









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159 



of grouting. In the present method, a large percentage of the grout 
goes beyond the limits of the theoretical area desired to be conso- 
lidated and is wasted. 

Another need is the development of tools for obtaining the in 
situ unconfined compressive strength (or shear strength) of the soil 
after it has been grouted. 

Further research is needed to determine if the strength of a 
grout material can be found by testing the grout in a gelled condi- 
tion in the laboratory, and then relating this strength in some man- 
ner to unconfined compressive strength in a standard soil material. 
This test might also be used to evaluate the amount of grout con- 
centration required for a specific job application. This could re- 
sult in a less expensive grout, since the solids used to gain con- 
centration are the expensive ingredient of the grout. There is also 
still a need for further improvement in the basic grouting materials, 
so study should proceed along this line to develop a less expensive 
grout. 

Different approaches can also be taken to the grouting opera- 
tion. In certain areas of the world, two different material in- 
jections are made during grouting; portland cement grout is injected 
throughout the area to fill the larger voids with an inexpensive 
grout, followed by an injection of chemical grout to fill the finer 
voids. This technique might be changed by having a better grout 
fluid that would obtain the desired results in all the pore spaces, 
and the time and cost of making two individual grouting passes 
across an area could be effectively reduced. 

The area of grid patterns and injection pipes might be im- 
proved. Where grout rods are driven into the ground as injection 
pipes, better and more efficient driving and pulling equipment are 
needed. The current equipment used is simply adapted to this ap- 
plication from its normal use, so that efficiency is usually sacri- 
ficed for expediency. The track drill and jack hammer used to 
drive the rods in the ground turn counterclockwise while moving up 
and down; therefore, these tools tend to rotate the pipe in the di- 
rection that unscrews the joints. A paving hammer is also used, it 
is somewhat better because it does not rotate while it reciprocates. 
Equipment used to withdraw the pipe could be improved, here again, 
equipment now in use are simply modifications of equipment designed 
for other purposes. 

The development of grout for backpacking tunnel liners might 
take a new approach to the type of material used. Current prac- 
tice is to use a grout material which solidifies and fills the 
void space around the ring, so a portland cement slurry has usually 
been utilized. A new grout might not necessarily be required to 
solidify, as the sediments surrounding it are not cemented together; 
therefore, this grout (or filler) might only be composed of solids 

160 





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161 



which are the same character as the surrounding sediments. A 
slurry of water and solids could be placed in the annul us between 
the liner and the in situ sediments, thus filling this void quickly 
and completely to reduce settlement. This type of filler might 
be suitable for injection into each individual liner section as it 
is placed. Placing portland cement grout into each individual liner 
section presents many problems, as this grout slurry cannot be main- 
tained for a very long period of time without setting. Generally 
the void is not filled behind each individual liner section as it is 
put in place, but two or more sections are grouted at one time. 

Hutchinson et al (59) have recommended improvements to the 
slurry trench and diaphragm wall construction procedures. These 
improvements involve further research to improve the fluid loss pro- 
perties of bentonite slurry for use in slurry trenches, and to de- 
velop a method for on-site analysis of the slurry properties. Other 
questions that should be answered include the effects of sand in the 
slurry to aid in filter cake formation in gravel formations, the ef- 
fects of cement contamination upon the slurry properties and the 
problems of the slurry displacement by the concrete. An area which 
also should be investigated is the use of polymers to replace the 
bentonite slurry. Considerable work is being done by the oil field 
service companies on polymers, since they are not toxic and are bio- 
degradable in nature. 

Research should also be done on the concrete used for the dia- 
phragm wall to provide better watertightness and continuity across 
panels (62), as well as techniques and cement compositions required 
for placing the concrete in narrow, deep trenches. 



162 



12. CONCLUSIONS 



This study of current grouting practices in the United States 
and Europe has highlighted several areas from which a number of con- 
clusions are warranted. These are as follows: 

1. Site investigation procedures are well established using 
conventional methods for determining grain size and per- 
meability in laboratory tests with soil samples. It is 
very difficult to recover samples of undisturbed cohe- 
sionless soil, so most samples are disturbed and must be 
recompacted before testing. This gives a wide variation 
in test results. Tests are standardized for obtaining 
in situ permeability, but these tests are not used wery 
often in a site investigation. 

2. Site investigations in the United States are normally 
the responsibility of consulting engineer companies who 
engage soil specialists to conduct the investigation. 

In England, consulting engineers who have complete soils 
and foundation analysis capabilities within their organi- 
zations are used for the planning and site investigation. 
Elsewhere in Europe, the grouting companies are capable 
and qualified to conduct the site investigation, and of- 
ten are engaged to do so. These investigations are 
usually more thorough than in America because they are 
conducted with grouting in mind as a possible construc- 
tion method. 

3. The amount of money allotted for site investigation in 
the average United States construction project is usual- 
ly a \/ery small percentage of the total cost, so the 
number of test borings is kept to a minimum. It is 
assumed that the soil layers remain constant across the 
area, but this is often not true. 

4. Other than obtaining samples or checking permeability, 
there are normally no in situ tests conducted in the 
site investigation which are repeated after grouting 

to determine the results of the grouting. Some in situ 
testing devices have been used in cohesive soils, but 
it is not known whether these tools would be applicable 
to cohesionless soils or to consolidated cohesionless 
soils after grouting. 

5. Grouting is seldom included in the initial specifica- 
tions for construction work in the United States; 
rather, conventional methods for cut-and-cover or soft 
ground tunneling, such as soldier beam and lagging, 
dewatering, underpinning, and compressed air excavation, 

163 



are usually specified, and grouting is used only in 
emergency situations. In European operations, grout- 
ing is given initial consideration in many underground 
construction projects for such purposes as: (1) stabi- 
lizing soil for simplified excavation of tunnels; (2) 
strengthening soil under buildings or utilities in 
place of underpinning; (3) waterproofing areas between 
sheet steel or concrete diaphragm walls; or (4) instal- 
lation of slurry trenches in cut-and-cover construction. 

6. Grout materials are available in a wide variety of 
strengths, viscosities and cost, but most are rela- 
tively expensive. Selection of proper grout can be 
made to fit the job purpose after a site investiga- 
tion has disclosed the soil is groutable and the soil 
properties are determined. 

7. In the construction or grouting business, there are no 
standard tests of cement grout to determine setting 
time or pumping time. There are tests in the oil well 
grouting field which could be applicable, such as thicken- 
ing time and pumpability tests which are normally made 
on a laboratory consistometer. 

8. Tests are not normally conducted on chemical grouts to 
determine physical properties, except when injected 
into soil samples. There is an ASTM test for uncon- 
fined compressive strength in cohesive soil, but there 
is no standard test for cohesionless soil or for such 
soil recompacted and grouted. 

9. Many of the chemical grouts being used are toxic in 
some manner, and a few grouts are now prohibited from 
use by environmental authorities in some European 
countries. 

10. There are mathematical approaches for planning of 
grouting operations; but most grouting specialists 
agree that the theoretical considerations are useful 
only in preliminary planning, so usually the grout 
plans are based largely on their past experience. 

11. Several injection techniques are presently used suc- 
cessfully in grouting. The procedures can be designed 
to use methods best suited for a particular job. This 
also holds true for mixing and pumping equipment, but 
the common practice is for the grouting company to use 
the equipment which they have been using on past jobs. 

12. Most of the grouting companies in Europe use a special 
injection pipe in boreholes to provide selective 

164 



grouting. Special packers are used on an inner pipe to 
straddle sleeve-covered, pre-drilled holes in the outer 
plastic pipe. This is an excellent grouting tool, but 
the United States companies have used this type of equip- 
ment very little. 

13. European grouting companies operate from sophisticated 
grouting houses or vans. Their jobs are controlled by 
automated mixing and injection pumps, and flow rate and 
injection pressures are recorded during a job to sub- 
stantiate grouting progress. The United States grouting 
firms do not possess such equipment, nor do they develop 
detailed records of their operations. 

14. Standard field procedure for a grouting operation in the 
United States seems to be the injection of as much grout 
in as short a time as possible. Such procedure reduces 
labor and equipment costs, but tends to overrun the 
amount of grout needed. Undoubtedly this is done because 
the pay item for the grouting contractor is usually based 
on the amount of grout injected, and a guaranteed job is 
not required. In contrast, many European grouting firms 
are paid on the basis of soil grouted, and definite re- 
sults are specified to be achieved. 

15. There is no method available to determine grout distribu- 
tion during the grouting operation. There are only a 

few methods now practiced to check the results of a grout- 
ing operation. Performance is determined when excavation 
is made through the grouted area. Laboratory examination 
of cores before and after a job is sometimes used to de- 
termine effectiveness of grouting. Reduction of existing 
water flow can be measured to find results. Settlement 
or rise of nearby buildings is another guide in evaluat- 
ing the grouting results. 

16. The use of bentonite slurries for temporary ground sup- 
port in trenches and boreholes is common practice with 
some construction companies, but there is insufficient 
information about the action of the slurry in this ap- 
plication. Slurry trenches have been used extensively 
in Europe, but have been used only recently in the 
United States to any degree. This method will probably 
be used increasingly through the next few years as more 
engineers become aware of its advantages and companies 
acquire the equipment to perform the operation. 

17. Tieback anchorages are a standard practice used by many 
companies, particularly in Europe. The technology has 
been well documented in publications, and usage of this 
tieback system seems to be growing in the United States. 

165 



18. Ground support by freezing in excavation of cohesionless 
soils is not used very much. It is a system that can be 
used for any shape configuration; but the technology is 
centered in only a few companies, and the work is rela- 
tively expensive compared to grouting or other means of 
support. 

19. Contractural arrangements in the United States differ 
significantly from those in Europe. European practices 
are much more flexible, and they permit private companies 
to share their expertise in planning of the construction 
work. This is never allowed in the United States con- 
tracts; companies must submit to strict specifications 
which have long been outdated in more progressive, under- 
ground construction practices. 

20. The grouting or backpacking for tunnel lining has not 
varied from portland cement grout. Improvements might 
be made in this application, or grout material used to 
provide lower costs or more efficiency. 



166 



13. RECOMMENDATIONS 



The following recommendations are made as a result of this 
study: 

1. Efforts should continue through workshops and confe- 
rences to further educate designers, engineers and 
constructors concerned with underground construction 
on the necessity of a thorough site investigation 
procedure. Ground conditions should be determined 
specifically enough to permit a realistic considera- 
tion of all methods of construction, including 
grouting. 

2. A demonstration project should be initiated to test 
the Menard Pressuremeter, the Iowa Bore-Hole Direct 
Shear Test Device, and the Goodman Jack in cohesion- 
less soils before and after grouting with various 
chemical grouts to attempt to determine a relation- 
ship to the unconfined compressive strength. It is 
also recommended that other known methods be investi- 
gated to accomplish this aim. 

3. The Delft (Holland) Soil Mechanics Laboratory Soil 
Sampler should be tested in the same demonstration 
project to determine the feasibility of its use to 
obtain undisturbed samples in the cohesionless 
soil before and after grouting. 

4. A standard test should be adopted for cement grout 
setting time and pumpability for use in coarse sand 
or gravel, possibly patterned after API tests used 
in oil well grouting work. 

5. A standard laboratory test procedure should be 
established for obtaining unconfined compressure 
strength of grouted samples of cohesionless soil. 

A standard for preparation of the sample should also 
be a part of the procedure. 

6. A method should be developed to determine the dis- 
tribution of grout during the grouting operation. 
This is an aspect of grouting which would find im- 
mediate use in all countries. It could conceivably 
lower the grouting costs appreciably, since knowing 
the grout distribution pattern would result in using 
less grout. 

7. A study should be made of other materials which might 
be substituted for cement in backpacking of tunnel 

167 



liners, in order that backpacking could be done 
immediately after each liner section has been set 
during the tunneling operation. A water slurry 
of various sands or pulverized fly ash should be 
investigated. 

8. The methods and techniques for ground excavation by 
freezing should be compiled from many sources into 
one volume as a guide for conducting satisfactory 
freezing operations. 

9. Efforts should be initiated by U. S. Government 
agencies to modify existing laws to change the con- 
tractual arrangements, so that the grouting con- 
tractor can negotiate directly with the contracting 
officer or owner, rather than being forced to have 
the general contractor act as his agent. This will 
give increased flexibility to working systems, and 
result in savings through contractor incentives to 
submit alternate proposals at a time in the bidding 
process when these alternatives may be reflected in 
the contract specifications. 



168 



M. REFERENCES 



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Engineers. 

b. Engineer Manual EM 1110-2-3502 , Foundation Grouting: 
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d. TM 5-818-6 and AFM 88-32 , Grouting Methods and 
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of Greater Chicago, July 1975. 

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169 



9. "Chemical Grout Seals Shafts Through Wet Sand," Construction 
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20. Mincheff, E. E. , "How to Stabilize and Level a Tank That is 

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170 



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26. Peck, R. B. , Hendron, A. J., Jr., and Mohraz, B. , "State of 

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171 



36. "Grouting of Foundation Sands and Gravels," Technical Memorandum 

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41. Skipp, B. 0. and Renner, L. , "The Improvement of the Mechanical 

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42. Cunningham, L. J., "The Use of Chemicals in Mine Grouting," Sixty- 

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172 



51. Amer, S. , Baguelin, F., Jezeguel , J. F. and LeMahartc, A., 

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53. Brochure, "Goodman Jack," Slope Indicator Company, 3686 Albion 

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55. Tamaro, George, "Concrete and Slurry Walls Using Slurry Trench 

Construction," Soil Mechanics and Foundation Engineers 
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56. Galler, Sol, "Slurry Wall Technique Expedites Subway Construction," 

Public Works Magazine , August 1973. 

57. Brochure, "Cast-in-Situ Diaphragm Wall," Soletanche, Paris, France. 

58. Francs, E. Colas Des, "Prefasif Prefabricated Diaphragm Walls," 

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"The Properties of Bentonite Slurries Used in Diaphragm 
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M. , Conference on Diaphragm Walls and Anchorages , September, 
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March 1968. 



173 



64. Earth Manual, U.S. Department of Interior, Bureau of Reclamation, 

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D.C., 1974. 

65. Bing and Jackson, Bureau of Standards Bulletin 14, 75 (1918). 

66. Cambefort, Henri, "In,yecci6n de Suelos ," Ediciones Omega, S.A., 

Casonova, 220 - Barcelona, Spain, 1968. 

67. "The French Have a Way with Grout Curtains," Engineering News- 

Record , April 25, 1963, pp. 32-33. 

68. "PANASOL" Prefabricated Retaining Walls, Brochure, Soletanche 

Entreprise, 7 Rue de Logelbach, Paris 

69. "Time Lag and Soil Permeability in Groundwater Observations, 

Bulletin No. 36, Waterways Experiment Station, Corps 
of Engineers, Vicksburg, Mississippi, April 1951. 

70. Wineland, John D. , "Borehole Shear Device," ASCE Proc. of Conf. 

on In Situ Measurement of Soil Properties, Vol. I, pp. 511-522, 
June 1 - 4, 1975. 



174 



15, APPENDIX 

A. Glossary of Terms 

B. Bibliography 

C. Case Histories 

D. Testing Information 

1. In Situ Permeability Test Procedure 

2. Laboratory Grout Distribution Tests 

E. Sample Specifications 

F. Applicable Patents 

G. Grouting Specialists 

H. Grouting Material Suppliers 

I. Grouting Equipment Suppliers 

J. Bentonite Suppliers 

K. Current Research in Grouting Technology 



175 



A. GLOSSARY OF TERMS 



Activator - Catalyst or hardner, reactant - the chemical solution 
which causes a mixture to gel or set when mixed with the base solu- 
ti on . 

Alluvium - Clay silt, sand gravel or other rock materials trans- 
ported by flowing water and deposited in comparatively recent geo- 
logic time as sorted or semi sorted sediments, in riverbeds, estuaries 
and flood plains, on lake shores and in fans at the base of mounting 
slopes. 

Backpack Grouting - The filling with grout of the annular space be- 
tween the permanent tunnel lining support and the soil. 

Bentonite - A montmorillonite-type clay formed by the alternation 
of volcanic ash which swells in the presence of water. 

Catalyst - See Activator. 

Coefficient of Permeability - The rate of discharge of water under 
laminar flow conditions through a unit cross-sectional area of a 
porous medium under a unit hydraulic gradient and standard tempera- 
ture conditions. 

Changed Conditions or Differing Site Conditions - Subsurface or 
latent physical condition at the site differing materially from 
those indicated in a contract; or nature, differing materially 
from those ordinarily encountered and generally recognized as in- 
herent in work of the character provided for in the contract, 
which conditions can bring about an equitable adjustment to modify 
the contract. 

Compaction Grouting - Intruding a mass of viscous cement grout into 
cohesionless soil to fill voids and to compact the soil by pressure. 
If performed in cohesive soil this is known as Compensation or 
Displacement grouting. 

Consolidate, Consolidation,Grouting or Solidify - Terms applied to 
the binding together of soil particles into a mass of soil, such 
as occurs in permeation grouting (see permeation grouting). 

Cut-and-Cover Tunneling - A process of installing a structure below 
ground by excavating an area of sufficient width, constructing the 
permanent structure at the bottom of the excavation, and then restor- 
ing the ground surface over the structure. 

Deformability - A measure of the elasticity or stress deformation 
characteristics of the grout in the interstitial spaces as the 
earth mass moves. 

176 



Diaphragm Walls - The construction of a vertical, continuous concrete 
wall, cast in situ or made of precast concrete panels, in a narrow 
trench filled with bentonite slurry to form a structural retaining 
wall . 

Fracturing, Fracturing Treatment or Fracture Grouting - Grouting 
performed using an injection pressure considerably higher than the 
overburden pressure, which opens cracks or channels in the soil de- 
posit. The grout then fills these channels and forms lenses. 

Free Water (Groundwater) - Water that is free to move through a soil 
mass under the influence of gravity. 

Gel Time - See Setting Time. 

Groundwater Table (Free Water Elevation) - Elevations at which the 
pressure in the water is zero with respect to the atmospheric pressure, 

Grout - A suspended cement or clay slurry or a chemical solution that 
can be poured or forced into the openings between soil or rock par- 
ticles to solidify or to change the physical characteristics of the 
material . 

Groutability - The ability of soil to allow grout to be forced into 
the interstitial spaces between the particles. 

Groutability Ratio - The ratio of the 15 percent size of the forma- 
tion particles to be grouted to the 85 percent size of the grout 
particles (suspension-type grout). This ratio should be greater 
than 19 if the grout is to successfully penetrate the formation. 

Grout "Take" - The measured quantity of grout injected into a unit 
volume of formation or soils. 

Hydrostatic Head - The pressure in the pore water under static con- 
ditions; the product of the unit weight of the liquid and the dif- 
ference in elevation between the given point and the free water 
elevation. 

Injectability - See Groutability 

Joosten Grouting - The earliest of the chemical grout processes, 
originating in 1925. In this process, a sodium silicate solution 
is pumped into the soil as a grout pipe is advanced downward. The 
pipe is then flushed with water, and calcium chloride is pumped in 
as the pipe is retracted. A precipitate forms upon contact be- 
tween the two solutions. 

Mixed Face - The face of a tunnel which consists of soil and hard 
rock. 

177 



Mud Jacking - A process in which a hole is bored through a concrete 
slab which has subsided and a water-soil cement slurry is pumped under 
the slab to fill voids, raise the slab and support the slab. 

Mohr Circle - A graphical representation of the stresses acting on the 
various planes at a given point. 

Newtonian Fluid - A true solution which tends to exhibit constant vis- 
cosity at all rates of shear. 

Non-Newtonian Fluid - Not a true fluid which exhibits increasing vis- 
cosity at higher rates of shear. 

Perched Water Table - A water table usually of limited area maintained 
above the normal free water elevation by the presence of an interven- 
ing relatively impervious confining stratum. 

Permeability - See Coefficient of Permeability 

Permeation Grouting - Replacing the water or air in the voids of the 
soil mass with a grout fluid at a low injection pressure to prevent 
creation of a fracture, permitting the grout to set at a given time 
to bind the soil particles into a soil mass. 

Porosity - The ratio of the volume of the voids or pores to the total 
volume of the soil. 

Proprietary - Made and marketed by one having the exclusive right to 
manufacture and sell; privately owned and managed. 

Pumpability - A measure of the properties of a fluid or slurry grout 
to be pumped. 

Reactant - See Activator 

Resin - A synthetic addition or condensation polymerization substance 
or natural substance of high molecular weight, which under head, pres- 
sure, or chemical treatment becomes a solid. 

Setting Time - A term defining the hardening time of Portland Cement 
or the gel time for a chemical grout. 

Slurry - Suspension of cement or clays in water or a mixture of both. 

Slurry Wall - See Diaphragm Wall 

Slurry Trench - A relatively narrow trench which is usually dug with 
a clamshell while the excavated portion is kept filled with a bento- 
nite slurry to stabilize the walls of the trench. 



178 









Syne res is - When freshly prepared sodium silicate gel is placed in a 
closed glass container, a significant amount of water can be observed 
being extruded by the gel. This is the phenomenon of syneresis. 

Toxicant - A poisonous agent. 

True Solution - One in which the components are 100% soluble in the 
base solution 

Tube a' Manchette - A plastic tube (pipe) of approximately 1 1/2" 
inside diameter, perforated with rings of 4 small holes at intervals 
of about 12 inches. Each ring of perforations is enclosed by a short 
rubber sleeve fitting tightly around the pipe so as to act as a one- 
way valve when used with an inner pipe containing packing elements 
which isolate a hole for injection of grout. 

Tunnel Face - The principal frontal surface presenting the greatest 
area, such as the face of a pile of material, the point at which 
material is being mined. 

Unconfined Compressive Strength - The load per unit area at which 
an unconfined prismatic or cylindrical specimen of material will 
fail in a simple compression test. 

Void Ratio - The ratio of the volume of void space to the volume of 
solid particles in a given soil mass. 

Water-Cement Ratio - The ratio by weight of water to the total dry 
solids in a cement slurry. 

Water Intrusion - The flowing of water into unwanted areas, such 
as trenches and tunnels. 



179 



B. Bibliography 

GROUTING IN SOILS 

Allen, R. H. and Gal pin, J. W. , "An Example of Controlled Pregrouting in 
Shaft Sinking," AIMME, Technical Publication No. 2427 , February 1948. 

"AM-9 Chemical Grout," Technical Data, 1965, American Cyanamid Company, 
Wayne, New Jersey. 

Amer, S. , Baguelin, F., Jezeguel , J. F. and LeMahartc, A., "In Situ Shear 
Resistance of Clays," ASCE Proceedings of Conference on In Situ 
Measurement of Soil Properties , Vol. 1, pp. 22-24, June 1 - 4, 1975. 

Anderson, E. Roy and McCusker, T. G. , "Chemical Consolidation in a Mixed 
Face Tunnel," 1st North American Rapid Excavation and Tunneling 
Conference Proceedings , 1972, Chapter 21. 

Annett, S. R. , "Chemical and Physical Aspects of Grouting Potash Mine 
Shafts," Canadian Min. and Met. Bulletin 62 , pp 715-21, July 1969. 

"Applications Prove Chemical Grout Useful," Diamond Alkali's Siroc, 
Chemical and Engineering News 43: pp. 46-7, July 19, 1965. 

Ash, T. L.; Russel , B. E.," Rommel, R. R. , "Improved Subsurface Investi- 
gation for Highway Tunnel Design and Construction," Volume 1, 
FHWA-RD-74-29 , May 1974. 

Badger, W. W. and Lohnes, R. A., "Pore Structure of Friable Loess," 
Highway Research Record No. 429 : 14-23, 1973. 

Beard, D. C. and We/!, P. K. , Influence of Texture on Porosity and 
Permeability of Unconsolidated Sand," The American Association 
of Petroleum Geologists Bulletin , Vol. 57, No. 2, February 1973. 

Behre, M. C, "Chemical Grout Stops Water in Dump Fill with 70% Voids," 
Civil Engineer , 32: pp. 44-6, September 1962. 

"Bentonite for Civil Engineering," Street! ey Minerals Group, Berk 
Minerals Products Division, Basing View, Basingstroke, Hanks, 
England. 

"Better Contracting for Underground Construction," U.S. National Committee 
on Tunneling, National Academy of Sciences, Washington, D.C. 
PB 236973 , November 1974. 

Bing and Jackson, Bureau of Standards Bulletin 14, 75 (1918). 

"Bibliography on Chemical Grouting," ASCE, Journal, Soil Mechanics and 
Foundations Division , Vol. 92, No. SM6, November 1966. 

180 



Brockett, R. W. , "Survey of Modern Grouts and Grouting," Structural 
Engineer, No. 5, Vol. 52, Page A5, May 1974. 

Brown, D. R. and Warner, James, "Compaction Grouting," Journal of Soil 
Mechanics and Foundations Division ASCE , Vol. 99, SM8, August 1973. 

"Building Sites Stabilized with Grout," Engineering News -Record , V. 134, 
No. 2, pp. 68-9, January 11, 1945. 

Burmister, D. M. , "Physical, Stress Strain and Strength Responses of 
Granular Soils," ASTM Special Publication No. 322 , 1962. 

Calhoun, Max L. , "Pressure-Meter Field Testing of Soils," Civil 
Engineering , July 1969, pp. 71-74. 

Cambefort, Henri, Inyecci6n de Suelos," Ediciones Omega, S.A., Casonova, 
220 - Barcelona, Spain, 1968. (Spanish Edition). Also available 
in French. No English edition. 

Cambefort, H. and Caron, C. , "The Leaching of Sodium Silicate Gels," 
Proceedings of the 4th International Conference of Soil Mechanics 
and Foundation Engineering ."" 

Campbell, Chester W. , "Chemicals Seal Foundation for New York Building," 
Civil Engineering , October 1957. 

Caron, C. , "Development of Grouts for the Injection of Fine Sands," 
Grouts and Drilling Muds in Engineering Practice , Butterworths, 
London, 1963, pp. 136-141. 

Caron, C. , Del isle, J. P. and Godden, W. H. , "Resin Grouting with Special 
Reference to the Treatment of the Silty Fine Sand of the Woolwich 
and Reading Beds at the New Blackwell Tunnel," Grouts and Drilling 
Muds in Engineering Practice , Butterworths, London, 1963, pp. 
142-145. 

Chadeisson, R., "Results of Injections in Cohesionless Soils," Consulting 
Engineer , London, V. 24, No. 4, pp. 425-428, October 1963; No. 5, 
pp. 547-522, November 1963; No. 6, pp. 652-653, December 1963. 

"Chemical Consolidation in Civil Engineering Practice, " Geotechnical 
Pamphlet No. 7, Soil Mechanics Ltd., 1961. 

Chemical Grout Field Manual , 3rd Edition, Engineering Chemicals Research 
Center, American Cyanamid, Wayne, New Jersey, April 1966. 

"Chemical Grout Prevents Water Inflow," Coal Age , V. 67, p. 112, 
September 1962. 

"Chemical Grout Seals Shafts Through Wet Sand," Construction Methods 
and Equipment, May 1962. 

181 



"Chemical Grout Technique Solves Meramec Shaft Sinking Problem," 

Engineering and Mining Journal , V. 160, pp. 107-9, November 1959. 

"Chemical Grouting; Progress Report of the Task Committee on Chemical 
Grouting," ASCE Soil Mechanics and Foundations Division Journal , 
Vol. 83, No. SM4, Paper 1426, November 1957. 

"Chemicals Solidify Beach Sand," Southwest Builder and Contractor , 
May 14, 1965. : 

"Chemject to Prevent Seepage into Underground Structures," Chemject 
Corporation, 3521 N. Cicero Avenue, Chicago, Illinois 

Coates, D. F. , "Rock Mechanics Principles," Ottawa, Canada, Information 
Canada, Mines Branch Monograph 874 , Rev. 1970. 

Compton, A. J., "An Introduction to Alluvial Grouting," Structural 
Engineer, V. 52, No. 5, p. A-13, May 1974. 

Corps of Engineers EM 1110-2-3501 , "Foundation Grouting: Planning," 
July 1966. 

Corps of Engineers, EM 1110-2-3503 , "Foundation Grouting: Field 
Technique and Inspection," August 1963. 

Corps of Engineers, EM 1110-2-3502 , "Foundation Grouting - Equipment," 
April 1949. 

Corps of Engineers, EM 1110-2-3504 , "Chemical Grouting," May 1973. 

Corps of Engineers, TM 3-408, "Grouting of Foundation Sands and Gravels," 
June 1955. 

Crawhall, J. S., "Tunneling a Water-Bearing Fault by Cementation," 
Engineering News-Record , May 30, 1929, p. 874. 

Cunningham, L. J., "Use of Chemicals in Mine Grouting," Canadian Mining 
and Metals Bulletin 55 :480-3, July 1962. 

"Cut-and-Cover Tunneling Techniques," Vol. 1, Report No. FHWA-RP-73-40 , 
February 1973. 

"Cyanaloc 62 Chemical Grout," Explosives and Mining Chemicals Department, 
American Cyanamid Company, October 1962. 



Delft Soil Mechanics Laboratory, Brochure, 1974, Stieltjesweg 2, P. 0. 
Box 69, Delft, Holland. 

Dempsey, J. A. and Moller, K. , Grouting in Ground Engineering, Institute 
of Civil Engineers, London, 1970. 

182 



Department of the Army, Office of the Chief of Engineers, EM 1110-2-1906 , 
"Laboratory Soils Testing," November 1960. 

Department of the Army and Air Force, TM 5-818-6 , AFM 88-32, "Grouting 
Methods and Equipment," February 1970. 

Dixon, Schaefer J., and Jones, Walter V., "Soft Rock Exploration and 
Pressure Equipment," Civil Engineering , October 1968, p. 34. 

Dorion, G. H. and others, "Permeability of Sand Stabilized with Chemical 
Grout," ASTM Bulletin , December 1960, p. 34-5. 

"Driving a Difficult Tunnel in Soft Ground," Engineering News -Record , 
pp. 507-13, April 1935. 

Dumbleton, M. J., "Some Sources of Information for Site Investigations," 
Ground Engineering , Vol. 7, No. 3, May 1974. 

Earth Manual , U.S. Department of Interior, Bureau of Reclamation, 2nd 
Edition, U.S. Government Printing Office, Washington, D.C. 1974. 

Einstein, H. A. and Schnitter, G., "Selection of Chemical Grout for 
Mattmark Dam," Proceedings of Soil Mechanics and Foundation Div ., 
Vol. 96, SM6, pp. 2007-2023, November 1970. 

Elston, J. P. and Kravetz, G. A., "Discussion of Field Experiences with 
Chemical Grouting," by M. Polivka and L. P. Witte and J. P. 
Gnaedinger, ASCE Soil Mechanics and Foundation Div. Journal , Vol. 
83, No. SM4, Part 1, Paper 1430, November 1957. 

EM-1110-2-3501 , Corps of Engineers, "Foundation Grouting: Planning," 
July 1966. 

EM-1 11 0-2-3502 , Corps of Engineers, Foundation Grouting: Equipment," 
April 1949. 

EM 111 0-2-3503 , Corps of Engineers, Foundation Grouting: Field 
Technique and Inspection," August 1963. 

EM 1110-2-3504 , Corps of Engineers, "Chemical Grouting," May 1973. 

"Engineering Properties of Three Sand-Gel Systems," Final Report No. 121, 
Mass. Institute of Tech., Cambridge, Mass., August 1961. 



Fawcett, David F., Journal of Soil Mechanics and Foundation Division , 
ASCE, Vol. 99, SM8, August 1973, pp. 638-639. 



183 



Fern, K. A., "Application of Polymerization Techniques to the Solution 
of Grouting Problems," Grouts and Drilling Muds in Engineering 
Practice , Butterworths, London, pp. 146-149, 1963. 

Flatau, A. S., Brockett, R. W. , Brown, J. V., "Grouts and Grouting - 
A Survey of Materials and Practice," Civil Engineering and Public 
Works Review, July 1973. 

"French Have a Way with Grout Curtains," Engineering News-Record , April 
25, 1963. 



Glossop, R., "A Classification of Geotechnical Processes," Geotechnique , 
London, 2,1, March 12, 1950. 

Glossop, R. , "The 8th Rankine Lecture, The Rise of Geotechnology and its 
Influence on Engineering Practice," Geotechnique , V. 18, March 1968. 

Glossop, R. , "The Invention and Development of Injection Processes," 
Part I - 1802-1850, Geotechnique , V. 10, No. 3, Sept. 1961: 
Part II - 1850-1860, Geotechnique , V. 11, No. 4, Dec. 1961. 

Glossop, R. , "The Rise of Geotechnology and its Influence in Engineering 
Practice," Geotechnique , V. 18, p. 105-150, March 1968. 

Gnaedinger, J. P., "Symposium on Grouting: Grouting to Prevent Vibration 
of Machinery," ASCE, Soil Mechanics and Foundations Division Journal , 
Vol. 87, No. SM2, April 1961. 

Golder, H. Q. and Gass, A. A., "Field Tests for Determining Permeability 
of Soil Strata," ASTM Special Technical Publication No. 322 , 1962. 

Golder, H. Q. and Harding, J. J. B. and Sefton Jenkins, R. A., "An 
Unusual Case of Underpinning and Strutting for a Deep Excavation 
Adjacent to Existing Buildings," Proceedings of the 5th International 
Conference of Soil Mechanics and Foundation Engineers , 2, p. 413, 1961. 

"Goodman Jack," Brochure, Slope Indicator Company, 3686 Albion Place North, 
Seattle, Washington 98103, July 1975. 

Graham, J. R. and Karpoff, K. P., "Chemical Grouting Investigations on 
Navajo Standstone, Glen Canyon Dam, Colorado River Storage Project," 
Lab Report No. C-1064 , Cone, and Struc. Branch, U.S. Bureau of 
Reclamation, Denver, Colorado, October 1963. 

Graham, J. R. , "Chemical Grouting of Soil and Rock," For Presentation 
at 1967 Earth Control and Investigations Course and Concrete Control 
Course, U.S. Bureau of Reclamation, Denver, Colorado. 

Granton, I.C. and Frazer, H. J., "Systematic Packing of Spheres with 
Particular Relation to Porosity and Permeability," Journal of 
Geology , Vol. 43, No. 8, 1935. 

184 



Greenwood, D. A. and Raffle, J. F. , "Formulation and Application of Grouts 
Containing Clay," Grouts and Drilling Muds in Engineering Practice , 
Butterworths , London, pp. 127-130, 1963. 

"Grout Curtain Seals Excavation," Engineering News-Record , November 28, 
1968. 

"Grout Selection: A New Classification System," by I. C. Hilton, 
Civil Engineering (London), September 1967. 

"Grouting with Bentonite," Concrete , V. 44, No. 7, p. 28, July 1936. 

"Grouting in Dry Sands," American Cyanamid Company, Princeton, New 
Jersey, October 2, 1962. 

Grouting Inspector's Manual , The Metropolitan Sanitary District of 
Greater Chicago, July 1975. 

Grouting Methods and Equipment, TM 5-818-6 , AFM 88-32 , February 1970. 

"Grouting - River Tunnel in England Made Dry by Grouting," Engineering 
News-Record , March 21, 1932, p. 430. 

"Grouting Design and Practice," Consulting Engineer (London) October 1969. 

"Grouting-Pumping Equipment," Eric Heaton, Mining in Canada, November 1968. 

Grouts and Drilling Muds in Engineering Practice , Butterworths, London, 
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Society of Soil Mechanics and Foundation Engineering of the 
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"Grouts andGrouting Materials, Applications and Plant," Civil Engineering 
and Public Works Review , London, July 1973. 

"Guide Specifications for Chemical Grouts," Journal of Soil Mechanics 
and Foundation Division , Vol. 94, SM2, March 1968. 

Haffen, M. and Janin, J., "Grouting Cohesionless Water-Bearing Soils 
in City Tunnels," Proceedings, First North American Rapid 
Excavation and Tunneling Conference , Chapter 85, 1972. 

Handy, R. L. and Williams, W. W. , "Chemical Stabilization of an Active 
Landslide," ASCE Civil Engineering , Vol. 37, No. 8, pp. 62-65, 1967. 

Heaton, Eric, "Grouting," Mining in Canada , Feb., Mar., June, Nov., Dec, 
1968 and March 1969 (Series of 6 Articles) 

Hegarty, A., "Chemical Grouting," Mining Magazine , p. 20-23, July 1960. 

185 



"Herculox Resin Grout," Technical Data Sheet PGS-0003, Halliburton 
Services, Duncan, Oklahoma. 

Hilton, I. C, "Grout Selection: A New Classification System," Civil 
Engineering , September 1967 (London). 

Hower, W. and others, "Fluid Grout for Water Control," Petroleum 
Engineer 39: B 26-9, June 1958. 

Hurley, Claude H. and Thornburn, Thomas H. , "Sodium Silicate Stabilization 
of Soils - A Review of the Literature," VILV-ENG-71-2007 , University 
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Hvorslev, M. J., "Time Lag and Soil Permeability in Groundwater 
Observations," Bulletin No. 36, Waterways Experiment Station, 
Corps of Engineers, U.S. Army, Washington, D.C. April 1951. 

Imako, Minoru, "Chemical Grouting Material of the Sodium Silicate, 
Sodium Aluminate System," Tokyo University, Chemical Abstract 
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"Injectrol® G Silicate Grout," Halliburton Services Technical Data 
Sheet PGS-0036. 

Intrusion Prepakt, Inc., Cleveland, Ohio, Special Report No. 102. 

Ischy, E. and Glossop, R., "An Introduction to Alluvial Grouting," 
Institute of Civil Engineers , Paper No. 6598. 

Janin, Jean and LeSciellour, Guy, "Chemical Grouting for Paris Rapid 
Transit Tunnels," Journal of Construction Division, ASCE , 
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"Japanese Tackle Water to Drive Record Tunnel," Engineering News - 
Record , pp. 16-17, April 4, 1974. 

Jones, Chester W. , "The Permeability and Settlement of Laboratory 
Specimens and Sand-Gravel Mixtures," Symposium on Permeability 
of Soils, ASTM Special Publication No. 163 , June 1954. 

Jones, G. K. , "Chemistry and Flow Properties of Bentonite Grouts," 
Grouts and Drilling Muds in Engineering Practice , Butterworths, 
London, p. 22-28, 1963. 

Joosten, J. H. , "The Joosten Process," Chemical Soil Solidification 
Company, 7650 S. Laflin Street, Chicago, Illinois 60629. 



Karol , R. H., "AM-9 Admixture for Cement," American Cyanamid Company, 
Wayne, New Jersey, January 1961. 

186 



Karol , R. H. , "Chemical Grouting Technology," Journal SM & F Pi v. SMI , 
Vol. 94, January 1968. 

Karol, R. H. , "Chemical Grouts and Field Grouting," American Cyanamid 
Company, 1963. 

Karol, R. H. , "Field Tests for Evaluating the Effectiveness of a 
Grouting Operation," American Cyanamid Company, 1960. 

Karol, R. H. , "Gel Extrusion from Grout Holes," American Cyanamid Company, 
Princeton, New Jersey, February 1963. 

Karol, R. H. , "Grout Curtains-Short Gel Times in Flowing Ground Water," 
American Cyanamid Company, 1961. 

Karol, R. H. , "Grouted Cutoff Malpaso Dam, Chiapos, Mexico," American 
Cyanamid Company, May 1963. 

Karol, R. H. , "Grout Viscosities," American Cyanamid Company, Princeton, 
New Jersey, March 1963. 

Karol, R. H. , "Physical Properties of Chemical Grouts," American Cyanamid 
Company, November 1963. 

Karol, R. H. , "Pumping Equipment for Chemical Grout," American Cyanamid 
Company, Princeton, New Jersey. 

Karol, R. H. , "Short Gel Times with Long Pumping Times," American 
Cyanamid Company, Princeton, New Jersey, April 1961. 

Karol, R. H., Soils and Soil Engineering , Prentice-Hall, 1960. 

Karol, R. H. and Swift, A. M., "Symposium on Grouting: Grouting in 
Flowing Water and Stratified Deposits," ASCE, Soil Mechanics and 
Foundations Division Journal , Vol. 87, No. SM2, pp. 125-145, 
April 1961. 

King, J. C. and Bush, E. G. W. , "Symposium on Grouting: Grouting of 
Granular Materials," American Society of Civil Engineers Proc , 
Vol. 87, SM2, No. 27911:1-32, April 1961. 

Kjellman, W. , Kallstenius, T. , and Wagner, 0., "Soil Sampler with Metal 
Foils," Proc. Royal Swedish Geotech. Inst . No. 1, 77 pp., 1950. 

Kravetz, G. A., "The Use of Clay in Pressure Grouting," Proceedings 
ASCE , Vol. 84, No. SMI, February 1958. 

Kutzner, C. and Ruppel , G. , "Chemical Soil Stabilization for Tunneling 

Under the Main Station in Cologne, as Part of the Underground 

Railway Construction," Strasse-Bruck Tunnel 22 , November 8, 1970, 
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187 



"Laboratory Soils Testing," EM 1110-2-1906 , Office of the Chief of 
Engineers, U.S. Army Corps of Engineers, November 1970. 

Lambe, T. W. , "Chemical Injection Processes," Annual Meeting ASCE, 
New York, October 1954. 

Lambe, T. W. , "Effect of Polymers on Soil Properties," Proceedings, 
3rd International Conference on Soil Mechanics and Foundation 
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Lambe, T. W. and Whitman, R. V., Soil Mechanics , New York, Wiley and 
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Lamberton, Bruce A., "Discussion of Strength Properties of Chemically 
Solidified Soils," Journal of Soil Mechanics and Foundation Div . 
ASCE , SM8, August 1973. 

Lancaster-Jones, P. F. F. and Gillott, C. A., "The Grouted Cutoff 
Curtain," Proc. of Inst, of C. E . (London) V. 14, October 1959. 

Leonard, J. T. , "Grouting, Clay-Based and Chemical," Engineer , 211: 
864-6, May 26, 1961. 

Leonard, M. W. and Dempsey, J. H. , "Clays for Clay Grouting," Grouts 
and Drilling Muds in Engineering Practice , Butterworths , London, 
pp. 119-126, May 1963. 

Leonard, M. W. and Moeller, K. , "Grouting for Support, with Particular 
Reference to the Use of Some Chemical Grouts," Grouts and Drilling 
Muds in Engineering Practice , p. 156-163, Butterworths, London, 
May 1963. 

Maillard, R. and Serota, S. , "Screen Grouting of Alluvium by the 
E. T. F. Process," Grouts and Drilling Muds in Engineering 
Practice , pp. 75-79, Butterworths, London, May 1963. 

Marsland, A. and Loudon, A. G. , "The Flow Properties and Yield Gradients 
of Bentonite Grouts in Sands and Capillaries," Grouts and Drilling 
Muds in Engineering Practice , p. 15-21, Butterworths, London, 
May 1963. 

Massargoh, Holtz, Holm and Fredricksson, "Measurement of Horizontal 
In Situ Stresses," ASCE Proc. of Conf. on In Situ Measurement 
of Soil Properties, pp. 266-286, 1975. 

Mayer, A., "Modern Grouting Techniques," Grouts and Drilling Muds in 
Engineering Practice , p. 7-9, Butterworths, London, May 1963. 

Mincheff, E. E. , "How to Stabilize and Level a Tank that is Settling," 
Fifth Annual Meeting, API Division of Transportation, Proc . , 
Philadelphia, Pennsylvania. 

188 



Minear, V. L. , "Use and Technique of Pressure Grouting in the Con- 
struction Industry," AIMME, Paper 2427 , February 1948. 

Mitchell, L. K. , "In-Place Treatment of Foundation Soils," Journal of 
Soil Mechanics and Foundation Division ASCE , Vol. 96, SMI , 
p. /3-II0, January 1970. 

Morgenstern, N. R. and Vaughan, P. R. , "Some Observations on Allowable 
Grouting Pressures," Proceedings of the Conference on Grouts and 
Drilling Muds in Engineering Practice , pp. 36-42, Butte rworths, 
London, May 1963. 

Mott, B. H. , "Solidifying Mines and Shaft Areas by Pressure Grouting," 
AIMME Technical Publication 2427, February 1948. 



Neelands, R. J. and James, A. N. , "Formulations and Selection of 

Chemical Grouts and Typical Examples of their Field Use," Grouts 
and Drilling Muds in Engineering Practice , Butterworths, London, 
pp. 150-155, 1963. 

Neumann, H. and Wilkins, L. S. , "Soil Solidification by Chemical 
Injection," Civil Engineering and Public Works Review , p. 635, 
June 1972. 

"New Chemical Grouting Processes," U.S. Waterways Experiment Station 
Bulletin (Soil Mechanics) V. 1, No. 9, p. 8, October 1, 1973. 

Numata, M. Maruyasha, T., and Kurosaki , "New Methods of Chemical 

Grouting to Solidify Loose Ground," Japan Society of C.E. No. 12 
February 1952. 



"PANASOL" - Prefabricated Retaining Walls, Brochure, Soletanche 
Entreprise, 7 Rue de Logelbach, Paris. 

"Paris Subway is Built in Grout Casing," Engineering News-Record . 
January 1, 1970, p. 2. 

Peck, R. B. , Hendron, A. J., Jr. and Mohraz, B. , "State of the Art of 
Soft Ground Tunneling," Proceedings, 1st North American Rapid 
Excavation and Tunneling Conference AIME , 1972. 

Perrott, W. E. , "British Practice for Grouting Granular Soils," Journal , 
American Society of Civil Engineers , SM6, 1965. 

Perrott, W. E. and Lancaster-Jones, P. F. F., "Case Records of Cement 
Grouting," Grouts and Drilling Muds in Engineering Practice , 
pp. 80-84, Butterworths, London, 1963. 



189 



Polivka, M. , Witte, L. P. and Gnaedinger, J. P., "Field Experience with 
Chemical Grouting," Journal, ASCE Soil Mechanics and Foundations 
Engineering Division , Vol. 83, No. SM2, Paper 1204, April 1957. 

"Pressure Grouting," U.S. Department of Interior, Bureau of Reclamation, 
TM-646 , June 1957. 

"PWG® Chemical Grout," Technical Data Sheet PGS-0006, Halliburton 
Services, Duncan, Oklahoma 73533. 

Raffle, J. F. and Greenwood, D. A., "The Relation Between the Rheological 
Characteristics of Grouts and Their Capacity to Permeate Soil," 
Proceedings of the 5th International Conference on Soil Mechanics 
and Foundation Engineers , 2, 789, 1961. 

Riedel , C. M. , "Chemical Soil Solidification in Foundation-Water Control 
and Tunnel Work," Sixth Annual Conference on Soils Mechanics and 
Foundation Engineering , University of Minnesota, Minneapolis, 
Minnesota, pp. 37-44, 1958. 

Riedel, C. M. , "Chemical Soil Solidification Work in Construction and 
Emergencies," Proceedings of the Conference on Soil Stabilization , 
Massachusetts Institute of Technology, Cambridge, Mass. June 18-20, 
1952, pp. 68-80. 

"Rockmakers," Architectural and Engineering News , March 1959. 

Schiffman, R. L. and Wilson, C. R. , "The Mechanical Behavior of 
Chemically Treated Granular Soils," ASTM 58 , 1958. 

Schmertmann, ASCE Proc. of Conference on In Situ Measurement of Soil 
Properties , June 1-4, 1973, Vol. 2. 

Scott, R. A., "Fundamental Considerations Governing the Permeability of 
Grouts and their Ultimate Resistance to Displacement," Grouts and 
Drilling Muds in Engineering Practice , pp. 10-14, Butterworths, 
London, 1963. 

"Shaft Sinking with Chemical Grout - Monktonhall Coal Mines," Coal Age , 
66:72, September 1961. 

"SIROC Grout Technical Manual," Diamond Alkali Company, Cleveland, 
Ohio, 1964. 

Skempton, A. W. and Cattin, P., "A Full-Scale Alluvial Grouting Test 

at the Site of Mangla Dam," Grouts and Drilling Muds in Engineering 
Practice , pp. 131-135, Butterworths, London, 1963. 

Skipp, B. 0. and Renner, L. , "The Improvement of the Mechanical Properties 
of Sand," Grouts and Drilling Muds in Engineering Practice , pp. 29-35, 
Butterworths, London, 1963. 

190 



"Sodium Silicate Stabilization of Soils - A Review of the Literature," 
by Hurley, Claude H. and Thornburn, Thomas, University of Illinois, 
Soil Mechanics Laboratory, Department of Civil Engineering and 
State of Illinois, Division of Highways, U.S. Department of 
Transportation, February 1971. 

"Soil Limits for Grout Injectivity," Graph - Halliburton Services, 
Duncan, Oklahoma 73533. 

"Soft Ground Tunnel Gives Jersey Sewer Contractor Hard Time," Engineer- 
ing News-Record , September 29, 1966, pp. 26-28. 

Spangler, M. G. and Handy, R. L. , Soil Engineering , Third Edition, Intex 
Educational Publications, 1973. 

"Soluble Silicates, Properties and Applications," Bulletin 17-1 . 
Philadelphia Quartz Company, 1964. 

"Special Chemical Grout Helps Driving Tunnel at Hunterston Nuclear 

Power Station," Civil Engineering and Public Works Review , London, 
July 1973. 

"Surface Grouting Stabilizes Cut," Engineering News-Record , September 12 
1963, 171:51. 



"T.D.M. Process," The Cementation Company Ltd., Ground Engineering 
Division, London. 

"Terra Firma Chemical Grout, a Precatalyzed Lino-Sulfonate," Concrete 
Chemicals Company, Cleveland, Ohio. 

Thatcher, John H. , "A Difficult Foundation Problem Solved with the 

Aid of Soil Solidification," Transactions of the New York Academy 
of Sciences , Sec. 2, Vol 27, No. 2, pp. 203-209. 

"Three Uses of Chemical Grout Show Versatility," Engineering News-Record , 
May 31, 1962, p. 168-70. 

"Time Lag and Soil Permeability in Groundwater Observations, Bulletin No . 
36 , Waterways Experiment Station, Corps of Engineers, Vicksburg, 
Mississippi, April 1951. 

TM-3-408, "Grouting of Foundation Sands and Gravels," Corps of Engineers, 
June 1955. 

TM 5-818-6, AFM 88-32, "Grouting Methods and Equipment," Department 
of the Army and Air Force, February 1970. 

"Tough Tunnel Bows to Chemical Grouting Baltimore's Susquehanna Water 
Tunnel," Engineering News-Record 168: 32-4, March 29, 1962. 

191 



Tschebotarioff , G. P., Soil Mechanics , Foundations and Earth Structures, 
McGraw Hill, New York, New York. 



"Underground Mining: Ground Support: Grout Available to Suit Any 
Application," Engineering and Mining Journal , 167: 432, 
June 1966. 

U.S. Department of the Interior, Bureau of Reclamation, TM 646 , 
"Pressure Grouting," June 1957. 



Vanoi , Dr. Ing. Diego, "Some Results in Freeway Tunneling by Means of 
Grouting Technique," Tunnel Symposium, Japan Society of Civil 
Engineers , 1970. 



Warner, James, "Strength Properties of Chemically Solidified Soils," 
ASCE, Journal Soil Mechanics and Foundation Pi v . , SM-1 1 , 
November 1972. 

Warner, James and Brown, D. R. , "Planning and Performing Compaction 
Grouting," Journal of Geotechnical Engineering Division, ASCE , 
Vol. 100, No. GT-6, June 1974. 

Wineland, John D. , "Borehole Shear Device," ASCE Proc. of Conf. on 
In Situ Measurement of Soil Properties , Vol. 1, pp. 511-522, 
June 1 - 4, 1975. 

Winter, Ernest and Rodriguez, Alvaro, "Evaluation of Preconsolidation 
and Friction Angle in Soils Using the Pressuremeter," ASCE Proc . 
of Conference on In Situ Measurement of Soil Properties , Vol . 1 , 
pp. 22-24, June 1 - 4, 1975. 

Welsh, Joseph P., "Soil Solidification," Metropolitan Section, Proc . 
Construction Group, ASCE , New York, New York, February 3, 1975. 

Wright, R. E. , "Chemical Grouting with Silicate-Bicarbonate and 

Silicate Aluminate Mixtures," Chemical Grout Symposium , Engineer's 
Club of San Francisco, Philadelphia Quartz Company of California, 
January 24, 1964. 



192 



SLURRY TRENCHES AND BOREHOLE STABILIZATION 



Barla, G. and Mascardi , C. , "High Anchored Wall in Genoa," Conference 
on Diaphragm Walls and Anchorages , Session IV, September 18-20, 
1974, London. 

Beard, D. C. and Weyl , P. K. , "Influence of Texture on Porosity and 
Permeability of Unconsolidated Sand," The American Association 
of Petroleum Geologists Bulletin, V. 57, No. 2, February 1973, 
p. 349-369. 

Behrendt, J., "The Slurry Trench Wall Construction Method Used in 
Underground Railway Construction in Cologne," Bauingeniur , 45, 
204, p. 121, 1970. 

"Bentonite for Civil Engineering," Streetley Minerals Group, Berk 
Mineral Products Division, Baginstroke, Hanks. 

"Bentonite Slurry Stabilizes Trench and Keeps Groundwater Out," 
Engineering News-Record , February 11, 1960, p. 42. 

Boyes, R. G. H. , Structural and Cut-Off Diaphragm Walls , Halsted Press, 
Wiley, New York 10016. 

"Cast-in-Situ Diaphragm Wall," Brochure, Soletanche, Paris, France. 

Cooke, P. W. , "Up-to-Date Techniques with Drilling Mud," Grouts and 
Drilling Muds in Engineering Practice , Butterworths , London, 
1963. 

"Concrete Displaces Slurry for Deep Perimeter Wall of Trade Center," 
Contractors and Engineers Magazine , February 1968, p. 26. 

Corbett, B. 0. and Stroid, M. A., "Temporary Retaining Wall Constructed 
by Berli noise System at Centre Beaubourg, Paris," Conference 
on Diaphragm Walls and Anchorages , Session 3, Paper 13, September 
18-20, 1974, London. 

Ebor, Gais, "First Construction of Tunnel Sections with a Supporting 
Arch Between Slurry Trench Walls in the Building of the Rapid 
Transit System in Munich," Eisenbahnig , Vol. 21, p. 268, 1970. 

El son, W. K. , "An Experimental Investigation of the Stability of Slurry 
Trenches," Geotechnique , Vol. 18, No. 1, p. 37, 1968. 

Fehlmann, H. B. , "The Application of Thixotropic Liquids Based on Bentonite 
for Subsoil Treatment," Proceedings of the 5th International Conference 
on Soil Mechanics and Foundation Engineering , 2, p. 765, 1971. 

193 



Flatau, A. S. , Brockett, R. W. and Brown, J. V., "Grouts and Grouting ■ 
A Survey of Materials and Practice," Civil Engineering and Public 
Works Review , London, July 1973. 

Fleming, W. G. K. , Fuchsberger, M. , Kipps, 0., and Sliwinski, Z. , 
"Diaphragm Wall Specification," Conference on Diaphragm Walls 
and Anchorages , Session 7, Paper 26, Sept. 18-20, 1974, London. 

Francs, E. Colas Des, "Prefasif Prefabricated Diaphragm Walls," 

Conference on Diaphragm Walls and Anchorages , September 18-20, 
1974, Session 3, Paper 11, London. 

Fuchsberger, M. , "Some Practical Aspects of Diaphragm Construction," 
Conference on Diaphragm Walls and Anchorages , September 18 - 20, 
1974, London. 



Galler, Sol, "Slurry Wall Technique Expedites Subway Construction," 
Public Works Magazine , August 1973. 

Germachlnig, C. and Mathian, J., "Diaphragm Walls as Temporary Cutoff 
Walls at Sites of the Rhone," Travaux , Vol. 52, No. 428, 1970. 

Gerwick, Ben C, "Slurry Trench Techniques for Diaphragm Walls in 

Deep Foundation Construction," Civil Engineering , December 1967. 

Hetherington, H. A., "Drilling Muds for Mineral Drilling and Water Well 
Construction," Grouts and Drilling Muds in Engineering Practice , 
Butte rworths, London, 1963. 

Hodgson, F. T. , "Design and Construction of a Diaphragm Wall at Victoria 
Street, London," Conference on Diaphragm Walls and Anchorages , 
Session 2, Paper 7, September 18 - 20, 1974, London. 

Hutchinson, M. T., Daw, G. P., Shotton, P, G, and James, A. N. , "The 
Properties of Bentonite Slurries Used in Diaphragm Wallinq and 
Their Control," Conference on Diaphragm Walls and Anchorages , 
September 18 - 20, 1974, London. 



"I.C.O.S. Company in the Underground Works," I.C.O.S., 1968. 



LaRusso, R. S. , "Wanapum Development Slurry Trench and Grouted Cutoff,' 
Grouts and Drilling Muds in Engineering Practice, Butterworths, 
London, 1963. 

"Leap-Frog Driving of Soldier Piles Cuts Slurry Trench Job Cost," 
Construction Methods , July 1968. 

194 



Leonard, M. S. M., "Precase Diaphragm Walls Used for the Motorway, Paris," 
Conference on Diaphragm Walls and Anchorages , Session 3, Paper 12, 
September 18 - 20, 1974, London. 

Lorenz, H. , "Utilization of a Thixotropic Fluid in Trench Cutting and 
the Sinking of Caissons, Grouts and Drilling Muds in Engineering 
Practice , Butterworths, London, 1968. 

Marker, H. , "The Use of Slurry Trench Wall Construction Method," 
Schweizerische Bauzeitung , Vol. 88, No. 33, 1970, p, 735. 

McKinney, J. R. and Gray, G. R. , "The Use of Drilling Mud in Large 

Diameter Construction Borings, Grouts and Drilling Muds in Engineering 
Practice , Butterworths, London, 1963, p. 218. 

Nash, J. K. T. L. and Jones, G. K. , "The Support of Trenches Using 
Fluid Mud," Grouts and Drilling Muds in Engineering Practice , 
Butterworths, London, 1963, p. 177. 

Sadlier, N. A. and Dominioni , G. C. , "Underground Structural Concrete Walls 
Grouts and Drilling Muds in Engineering Practice , Butterworths, 
London, 1963, p. 177. 

Saxena, S. K. , "Measured Performance of a Rigid Concrete Wall at the 
World Trade Center," Conference on Diaphragm Walls and Anchorages , 
Session 4, Paper 14, September 18 - 20, 1974, London. 

Schmidt, Birger, "Exploration for Soft Ground Tunnels - A New Approach," 
Study for UMTA - D0T/TSC-654 , 1974. 

Sliwinski, Z. , Fleming, W. G. K. , "Practical Considerations Affecting 
the Construction of Diaphragm Walls," Conference on Diaphragm 
Walls and Anchorages , September 18 - 20, 1974, London. 

"Slurry Trench Cutoff Wall Pierces Landslide Debris to Keep Site Dry," 
Engineering News-Record , November 13, 1975. 

"Special Rigs Go Through Rock and Wood to Form Slurry Trench," 
Construction Methods , July 1967. 

Spoor, Michael F. , "Definition by Remote Sensing and the Chemical 
Grouting of Subsidence Areas," U.S. Army Engineer District, 
Huntington, West Virginia, Corps -Wide Geology, Soils and Drilling 
Meeting , October 1 - 4, 1974, Dallas, Texas. 

Tamaro, George, "Concrete and Slurry Walls Using Slurry Trench Con- 
struction," Soil Mechanics and Foundation Engineers Conference , 
University of Minn., 1972 

195 



Thon, J. G. and Harlan, R. C. , "Slurry Walls for BART Civil Center 
Construction," Soil Mechanics and Foundation Division, ASCE , 
Journal , Paper 8361, September 1971, p. 1317. 



Verder, C. , "Excavation of Trenches in the Presence of Bentonite 

Suspension for the Construction of Impermeable and Load-Bearing 
Diaphragms," Grouts and Drilling Muds in Engineering Practice , 
Butte rworths, London, 1963. 

"Vibrating Beam Injects Thin Cutoff Walls," Engineering News-Record , 
November 27, 1973, p. 19. 



Xanthakos, Petros P., "Underground Construction," National Education 
Seminar , University of Illinois, April 1974. 



FREEZING 



Bookreiev, D. A., Waterproofing and Drainage of Defense and Non-Defense 
Structures , Government Publication of Construction Literature, 
Moscow, 1943. 

Brace, J. H. , "Freezing as an Aid to Excavation in Unstable Material," 
Transactions, ASCE , Vol. 52, 1904. 

Braun, Bernd, "Ground Freezing for Tunneling in Water-Bearing Soil 
at Dortmund, Germany," Tunnels and Tunneling , January 1972. 

Bubbers, B. L. , "Tunneling on the Brixton Extension of the Victoria 
Line, Tunnels and Tunneling , July 1971, p. 235. 

'Construction Freezing," Terrafreeze Corporation, Lorton, Virginia 22079. 

"Contractor Employs Deep Freeze," Mobay Chemical Company Builder News . 

Cross, B. , "Liquid Gas Freezes Bad Soil," Construction Methods and 
Equipment , New York, July 1964. 

"Deep Freeze to Keep Shaft in Dry," Engineering News -Record , September 3, 
1959, p. 25. 

Dumont-Vi Hares, A., "Underpinning the Companhia Paulista des Seguros 
Building, Sao Paulo," Geotechnique , London, March 1956. 

196 



Ellis, D. R. and McConnell , J., "The Use of the Freezing Process in the 
Construction of a Pumping Station and Storm-Water Overflow at 
Fleetwood, Lancashire, Proceedings, Institute of Civil Engineers , 
London, February 1959. 

Endo, K. , "Artificial Soil Freezing Method for Subway Construction," 
Civil Engineering in Japan , 1969, p. 103. 

Follenfant, H. G. and others, "Escalator Tunnel Victoria Line," 
Journal Institute of Civil Engineers , 1969, Paper 7270S 

"Freezing Makes Shaft Sinking Easier," Construction Methods and 
Equipment , New York, October 1954. 

Gail, Charles P., "Tunnel Driven Using Subsurface Freezing," Civil 
Engineering , May 1972, p. 37. 

Hashemi, Hadit and Sliepcevich, Cedomir M. , "Effect of Seepage Stream 
on Artificial Soil Freezing," Journal Soil Mechanics and Foundation 
Division, ASCE, SM3, March 1973. 



"Ice Wall Protects Shaft Excavation," American City , New York, April 1960. 

"Investigation of Description, Classification and Strength Properties of 
Frozen Soils," Vols. 1 and 2, Report 8 , Frost Effects Laboratory, 
U.S. Army Corps of Engineers, Hanover, N. H. , 1952. 

Kersten, Myles S. , "Thermal Properties of Soils," University of 
Minnesota Bulletin 28, Vol. 52, No. 21, June 1, 1949. 

Khakimov, K. R. /'Artificial Freezing of Soils - Theory and Practice," 
Israel Program for Scientific Translations , U.S. Department of 
the Interior, Washington, D.C., 1966. 



Latz, J. E. , "Freezing Method Solves Problem in Carlsbad, New Mexico 
Shaft," Mining Engineering , October 1952. 

Low, G. J., "Soil Freezing to Reconstruct a Railway Tunnel," Journal 
of the Construction Division, ASCE, Vol. 86, No. C03, Paper 2639, 
November 1960. 



Sanger, F. J., "Ground Freezing in Construction," Journal of Soil 
Mechanics and Foundation Engineering, ASCE, Vol. 99, No. SMI, 
January 1968. 

197 



Sayles, F. H. , "Studies in the Creep of Frozen Soils," Technical Report 
190 , U.S. Army Cold Regions Research And Engineering Laboratory, 
Hanover, New Hampshire, 1967. 

"Shaft Sinking Can be a Chilling Experience," Engineering News-Record , 
August 9, 1962. 

Shuster, John A., "Controlled Freezing for Temporary Ground Support," 
First North American Rapid Excavation and Tunneling Conference , 
1972, Chapter 49. 

Silinsh, J., "Freezing Keeps Shaft Dry and Holds Dirt in Place," 
Construction Methods and Equipment , January 1960. 

Smith, G. R. , "Freezing Solidifies Tunnel Shaft Site," Construction 
Methods and Equipment , October 1962. 

Stewart, G. C. , Gildersleeve, W. K. , Janpole, S. and Connolly, J. E. , 
"Freezing Aids Shaft Sinking," Civil Engineering ASCE, April 1963. 

"Swedes Quick-Freeze 39-Foot Tunnel Section," Engineering News-Record , 
October 29, 1970. 



Tsytovich, N. A. and Khakimov, K. R. , "Ground Freezing Applied to 

Mining and Construction," Proceedings - 5th International Conference 
on Soil Mechanics and Foundations, Paris, 1961. 



Vialov, S. S. , "Rheological Properties and Bearing Capacity of Frozen 
Soils," Translation No. 74 , U.S. Army Cold Regions Research and 
Engineering Laboratory, Hanover, N. H. , 1965. 



TIEBACK ANCHORAGES 



"Anchors Hold Down Tunnel Sealed in Steel," Engineering News-Record , 
June 9, 1960, p. 29. 

"Batter Piles Brace Sheeting Around Building Excavation," Engineering 
News-Record , March 11, 1965, p. 26. 

Booth, W. S., "Tiebacks in Soil for Unobstructed Deep Excavation," 
Civil Engineering , September, 1966, p. 46. 

"Bulkhead Tied Back to Soft Soil," Construction Methods , October 1967, 
p. 112. 



198 



Dietrich, M. , Chase, B. , and Teul , W. , "Tieback System Permits Uncluttered 
Site," Foundation Facts, Raymond International Vol. 7. 



Hanna, T. H. and Matallana, G. A., "The Behavior of Tied-Back Retaining 
Walls," Canadian Geotechnical Journal, 1970. 



Jones, N. C. and Kerkhoff, G. 0., "Belled Caissons Anchor Walls as 
Michigan Remodels an Expressway," En gineering News -Record , 
May 11, 1961, p. 28. 



Kastnor, R. and Lareal , P., "Experimental Excavation of Length 50m 
Supported by Strutted Cast Diaphragm Walls: An Analysis of 
Stress Distribution in the Struts," Conference on Diaphragm Walls 
and Anchorages , September 18 - 20, 1974, London. 



Littlejohn, G. S. , "Soil Anchors," Proceedings, Conference on Ground 
Engineering , London, June 1970. 

Littlejohn, G. S. and McFarlone, I. M. , "A Case History Study of Multi- 
Tied Diaphragm Walls, Conference on Diaphragm Walls and 
Anchorages, September 18-20, 1974, London. 

"Long Buried Tiebacks Leave Cofferdam Unobstructed," Construction Methods 
and Equipment , May 1966. 

Mansur, Charles, "Tieback Sheeted Excavations," Construction Excavations 
University of Wisconsin, April 30, 1971. 

Meissner, H. , "The Anchorage of Retaining Walls and Little Deformation," 
Bauingenieur , Vol. 45, No. 9, 1970. 

Nelson, James C. , "Earth Tiebacks Support Excavation 112 Feet Deep," 
Civil Engineering , November 1973. 

Ostermayer, H. , "Construction Carrying Behavior and Creep Characteristics 
of Ground Anchors," Conference on Diaphragm Walls and Anchorages , 
September 18 - 20, 1974, London. 

Reichenback, K. , "Tieback Anchoring of Excavation Walls During Building 
of Underground Railway Lines 7 and 9," Strasse, Brucke, Tunnel, 
Berlin 23, No. 1, 1971, p. 18. 



199 






Shannon, William L. and Strazer, Robert J., "Tied-Back Excavation Wall 
for Seattle Bank," Civil Engineering , March 1970, p. 62. 

"Soil Anchored Tie-Backs Aid Deep Excavation," Engineering News-Record 
August 10, 1967, p. 34. 



Wasser, Thomas D. and Darragh, Robert D. , "Tiebacks for Bank of 

America Excavation Wall," Civil Engineering, March 1970, p. 65. 






200 



CASE HISTORIES 

Exhibit A - Tunnel Grouting - Bart System - San Francisco, 
California 

Exhibit B - Chemical Grouting Beneath the Walt Whitman Bridge, 
Philadelphia, Pennsylvania 

Exhibit C - Grouting a Vehicular Tunnel in Alaska 

Exhibit D - Pregrouting for Tunnels under 26 Railroad Tracks, 
Pontiac, Michigan 

Exhibit E - Grouting for Sewer Line Support Near Metro Tunnel, 
Washington, D. C. 

Exhibit F - Grouting Overpass Piers on Route of Metro System, 
Washington, D. C. 

Exhibit G - Grout Curtain on Earthen Dam - Public Service 
Company of Oklahoma Reservoir #3, Washita, Oklahoma 

Exhibit H - Soil Consolidation for Tunnel Excavation, 
Washington, D. C. 

Exhibit I - Chemical Soil Stabilization for Florida Power 
Corporation - Unit No. 3 - Crystal River 



201 



EXHIBIT A 

CASE HISTORY 

TUNNEL GROUTING - BART SYSTEM 
SAN FRANCISCO, CALIFORNIA 



1. Statement of Problem 

Many times, the first contact to a grouting contractor from a 
tunneling contractor occurs when a problem is encountered with un- 
consolidated sand or water in large quantities. In this particular 
situation, the tunnel was being driven under air 90 feet below street 
level to a connection with the Civic Center Station of the Bay Area 
Rapid Transit (BART) system in San Francisco, California. Upon reach- 
ing the station, the tunnel would normally have been tied to the wall 
in a relatively simple operation since the air kept the water under 
control. However, when the tunnel was nearly at the station, it was 
necessary to stop driving the tunnel, fill the head of the shield 
full of cement, take the air off the tunnel and cease operating be- 
cause the concrete station wall had not yet been constructed. 

After the wall was built, the tunneling contractor was notified 
to finish the tunnel and connect it to the station wall. He was told 
that the traffic on the busy intersection of Market Street and Civic 
Center could not be stopped or detoured, so he would have to perform 
his work without the use of the surface area above the tunnel. He 
was also prohibited from using the normal procedure of dewatering 
the sand above the tunnel, since it might cause severe settlement 
problems on the buildings above. The formation was thought to be 
water saturated sand from 10 feet to 90 feet, or a head of 80 feet 
of water in an unconsolidated sand. 

The tunnel contractor was required to complete the tunnel and 
connect it to the concrete wall of the station. If the sand was 
wet and unconsolidated as suspected, it would not be possible to 
open a hole in the concrete wall and mine the sand for the tunnel 
unless some remedial procedures were taken. The tunneling con- 
tractor then contacted Halliburton Services in January 1969 to see 
if it might be feasible to consolidate the sand sufficiently by 
grouting to permit opening the wall. This approach seemed to be 
feasible. 

2. Site Investigation 



a. Site Examination 

A visit was made to the San Francisco site by Halliburton 
grouting specialists and the problem viewed from inside the 
tunnel and from inside the station. The possible location for 

202 



grouting equipment in the station area appeared to be satisfac- 
tory. 

b. Formation Sampling 

A sample of the ground water leaking into the tunnel was ob- 
tained, but it was not possible to obtain samples of the formation 
behind the concrete station wall because the tunnel contractor 
felt it would be too expensive. Since it was thought that the sand 
from inside the station was the same as behind the wall, it was de- 
cided that formation sand samples would be obtained from the inside 
of the concrete slurry wall being excavated at that time. The ex- 
cavation had reached a depth of about 46 feet below street level, 
so a formation sample was taken at that point. When the excavation 
reached the tunnel level at a 90 foot depth, a sample was also se- 
cured at that depth. 

c. Soil and Subsurface Analysis 

Initial laboratory tests were made to analyze the soil samples 
from the site. These were fine sand with a porosity of about 40% 
and a permeability of about 10"3 cm/sec. 

The grout tentatively selected was Herculox, a urea -formaldehyde 
chemical grout, which provided good strength characteristics. Re- 
compacted samples were grouted with the Herculox grout at the expected 
site temperature of 65°F. An unconfined compressive strength of 666 
psi was obtained as an average of three tests. This was considered 
sufficient to support the expected overburden and water head when the 
grouted soil was mined. 

3. Planning for the Grouting Operation 

a. Job Planning 

It was agreed that the grouting crew would come from personnel 
of the tunnel contractor and that Halliburton would furnish a grout- 
ing engineer to direct the grouting operation. Equipment, materials 
and chemical grout would be furnished by the grouting contractor. 
This included mixing and pumping equipment, miscellaneous valves, 
glands and grout injection pipes, as well as driving heads and pull- 
ing mechanism for the grout pipes. Pumps to be used were dual 
triplex plunger type positive displacement units made of non- 
corrosive materials. 



The grouting was planned to be accomplished through a series 
of holes approximately in line with the circumference of the tunnel 
bore and in the center portion of the tunnel area. Grouting nipples 
2 inches in diameter would be grouted into a hole drilled 18 inches 
deep in the 2 foot concrete wall and 2 inch full opening valves 

203 



would be placed on the nipples. The hole would then be completed 
through the other 6 inches of the wall. The grouting through the 
2 inch nipples would be accomplished by extending the proper length 
grout pipe through a packoff gland in the valve into the sand to be 
grouted, then pumping a predetermined amount of chemical grout each 
foot as the grout pipe was withdrawn. 

The grouting plan was then presented to the tunnel contractor, 
who agreed with the procedures as outlined. 

b. Cost Estimate 

The cost arrangement for this job as set forth below was also 
agreeable to the tunnel contractor. 

1. Mobilization and Demobilization - 

Lump Sum. 

2. Grouting Engineer - Fixed daily fee 

for each 8-hour shift or fraction 
thereof. 

3. Grout mixing and pumping equipment with 

all hoses - Fixed daily fee for each 
8-hour shift or fraction thereof. 
Payment to be per calendar day if on 
location not in use. 

4. Chemical Grout - Fixed price/gallon for 

each gallon mixed. 

5. Miscellaneous valves, packoff glands, 

grout pipes, driving and pulling 
mechanism - Lump Sum. 

4. Performing the Grouting Job 

Nine months had been required to complete all the preliminary 
work on this grouting operation. The tunnel contractor then pro- 
ceeded to drill the holes and grout all the 2 inch grout nipples 
in the concrete station wall in accordance with the plan submitted. 
Three months later, equipment and grouting chemicals were shipped 
to the site and the grouting engineer was ready to start the job. 

Grout pipes were driven into the formation initially to a 
depth of 6 feet through the grout nipples. Two or three holes 
were used to place grout through the rods. Predetermined amounts 
were pumped at one foot intervals while the grout pipe was with- 
drawn. Results were checked at this point because no exploratory 
investigation had been made prior to the job in the actual forma- 
tion. It was found that the sand had not been consolidated pro- 
perly and water flowed freely out of the open valves. This 
indicated that flowing water must be washing the grout away before 
it set. Since there was apparently flowing water present in the 
formation to be excavated, changes now had to be made in the grout 

204 



material and procedure to meet the unexpected conditions encountered 
behind the station wall. 

As a result of this initial grouting, the Halliburton Chemical 
Laboratory formulated a grout material with a setting time of 20 to 
30 seconds at the ground water temperature of 65° F to use to combat 
the flowing water. Due to the fast set, the grouting procedure had 
to be altered since the grout would probably set up in the pipes or 
grout the pipe in the sand using the planned procedure. 

The grouting engineer decided to grout directly through the 2 
inch pipe nipples into the sand and pump until an increase in pump 
pressure indicated that the grout had set. This procedure was tried 
through one pipe nipple. By drilling through the pipe into the 
grouted sand, it was found that the sand had been consolidated to a 
depth of about 18 inches. Grout was then pumped through the same 
pipe to consolidate the sand further. This technique was followed 
through each nipple in the concrete wall until the sand was conso- 
lidated to a distance of 5 to 6 feet from the station wall. The 
grout used in this operation was the Herculox grout, which provided 
high strength for the portion that was to be mined out to make the 
tunnel connection to the station wall. Figure C-l shows the grout- 
ing operation in process. 

The final step in the grouting operation was to grout the sand 
for appeoximately 25 additional feet to shut off any other water. 
This was accomplished using Injectrol® silicate grout, a less ex- 
pensive gel type grout. It was pumped through the grout pipes as 
attempted in the initial part of the job. This grouting was suc- 
cessful because the flowing water had been stopped by the initial 
grouting of the sand next to the station wall. Total grouting time 
was 3 weeks. 

The tunnel contractor then cut a hole in the station wall, 
mined out the consolidated sand and made the connection between 
the tunnel lining and the concrete station wall. Figure C-2 shows 
the hole through the concrete wall, and the consolidated dry sand 
behind it. Through the shield, which will be removed, the tunnel 
lining is visible. 

5. Conclusions 



A common difficulty found on most grouting jobs is 
the problem of obtaining prejob information on the 
condition of the formation to be grouted. In an 
effort to save money, no opening was made into the 
sand behind the station wall to find actual condi- 
tions before grouting started. The conditions 
found when grouting started were not what was ex- 
pected, resulting in a delay and a reassessment 
before grouting could be completed. With 

205 



Q 



equipment and personnel on the site, this was an 
expensive delay. 

It is essential to have a thorough on-site investi- 
gation with sufficient sampling to determine grouting 
feasibility. It would be preferable if permeability 
determinations and pumping data could be obtained in 
situ rather than by retrieving samples, since it is 
almost impossible to repack a sample to match the 
original formation characteristics. 






206 




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207 




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208 



EXHIBIT B 



CASE HISTORY 



CHEMICAL GROUTING BENEATH THE WALT WHITMAN BRIDGE 
PHILADELPHIA, PENNSYLVANIA 



1 . General 

The joint venture of Kuljian-DeLeuw Cather in designing the 
Philadelphia Broad Street Subway Extension encountered a problem as 
the proposed cut and cover subway excavation was extremely close to 
the pile supported East Pier of the Walt Whitman Bridge approach. 
Figure C-3 shows the proximity of the reinforced concrete box of 
the subway, and indicates the three rows of piles supporting the 
pier. Upon reviewing the soil data, the engineers wrote a broad 
specification for the chemical grouting of the granular soil around 
the piles in order to protect the pier during excavation and from 
the future vibration of subway traffic. 

Peter Kiewit and Sons Company was successful bidder on this 
$17,000,000 subway project. They retained the soils consulting 
firm of Woodward-Clyde and Associates of Philadelphia to deter- 
mine the most effective method and type of grout to utilize. 

2. Job Information 



Peter Kiewit 1 s subcontract for the chemical grouting gave the 
project engineer for the grouting firm the responsibility of de- 
termining the grouting pattern, material, mix, etc. Due to the 
find grained nature of the soil, it was elected to utilize Terra- 
nier "C" Chemical Grout, a product of ITT Rayonier, which had re- 
lative high strength, low viscosity, and is economical. As the 
borings indicated some difficulty would be experienced in conven- 
tional grouting techniques, it was elected to utilize the Stabi- 
lator Valve Tubing Method of grouting. Extensive experience in 
this system had been obtained when this method was introduced to 
the U. S. in grouting beneath the Florida Power Company's Nuclear 
Reactor at Crystal River, Florida. At this site, nearly 500,000 
gallons of Siroc, Siroc Cement and Terranier was injected to 
depths of 90 feet. Basically, the Stabilator System utilizes light- 
weight casing which has spring valves built into it on strategic 
centers. The casing is installed by using an Atlas Copco Crawler 
drill. Drilling bits are used and the casing attached to the drill- 
ing bit along with the casing knockoff bit. When the desired depth 
is reached, the casing bit is knocked off, the drilling rods ex- 
tracted, and the casing is then ready for grouting. A double packer 
is installed and the pump pressure forces the spring valve open, thus 
grouting the strata required. This drilling technique was developed 
in Sweden and has worked extremely well in glacial till and other 

209 



3 



I 

V) 



1 



c 










\/ 






J£e>/7£. - 




&rocs/ /c/Atrs - i/o/v<?d 



TYPICAL SECTION 



Figure C-3. Grouting setup for bridge support 

210 



similar soils which are normally a driller's nightmare. 

It was elected to utilize a grout pipe spacing of 5 feet on 
center, and in order to encompass the soil around the piles, five 
rows were required in one direction and 23 rows in the other di- 
rection. A depth of grouting four feet beneath the deepest piles 
and three feet above the tip of the shallowest pile was utilized. 

Grouting equipment consisted primarily of a mixing and pump- 
ing tank for the Terranier Chemical Grout and the catalyst, and 
two chemical grout pumps. Terranier Chemical Grout reacts with 
formaldehyde to form a permanent irreversible gel. This chemical 
reaction takes place within 24 hours in normal temperature condi- 
tions. In order to speed the gel time up, a metal salt, Sodium 
Dichromate is used, thereby allowing the gel time to be controlled 
from instant set to any desired time requirement. 

A study of the soil profile indicated that above the zone to 
be grouted there was a silty clay stratum impervious to chemical 
grout and the control of the grout travel from the bottom was ac- 
complished by injecting through the bottom valve a double volume 
of chemical grout. 

The basic pumping procedure utilized was to pump the two rows 
on either side of the pier with a predetermined volume of chemical 
grout having a gel time beneath 5 and 15 minutes. This in effect 
created a double cutoff wall and the interior row was then pumped 

to refusal . 

3. Job Results and Conclusions 

In order to analyze the results of the chemical grouting prior 
to excavation, borings were taken as shown in Table C-l. A marked 
increase was noted in the blow count. Also, prior to grouting, 
running sand stratas were encountered; these were not observed af- 
ter grouting. Further, a marked increase in the cohesion of the 
sand was observed along with a decrease in the permeability of the 
soil . 

It can be concluded that this chemical grouting operation was 
highly successful and will prevent any future movement of this pile 
supported pier from construction activity, the adjacent excavating 
or from the anticipated subway vibrations. 

The grouting contractor for the job was the SOILTECH Depart- 
ment of Raymond International, Inc. 



211 



Table C-l 
Test Boring Reports by Raymond Beneath Walt Whitman Bridge Overpass 

Philadelphia, Pennsylvania 



r ... ... ... 

Depth, 


General 


STANDARD PENETRA1 


"ION BLOW COUNT 


Location #1 


Location #2 


Before 


After 


Before 


After 


Feet 


Description 


Grouting 


Grouting 


Grouting 


Grouting 


5 




23/1 " 




17 




6 
7 


Miscellaneous Fill 




16 






8 




3 


4 


13 




9 












10 












11 




15 


16 


2 




12 












13 












14 












15 




3 


9 


9 




16 












17 












18 












19 












20 


Firm silty clay with 










21 


decayed vegetation 


10 


7 


14 


21 


22 
23 




















58 


24 










59 £ 


25 




30 


33 


27 


37 S 


26 










139 a 


27 
28 




36 






UJ 




100/2" 




55 o 


29 








30 


DC 
C£5 


30 










100/3" 


31 
32 






i i i 








38 


LU 

o 


40 




33 






67 M 






34 




40 








35 






97 s 






36 


Dense gravelly sand 




79 § 


28 




37 




64 


CD 






38 






69 






39 

40 








48 






41 












42 












43 




46 




38 




44 












45 

ii 




52 


— 1 


20 





212 



EXHIBIT C 

CASE HISTORY 

GROUTING A VEHICULAR TUNNEL IN ALASKA 



1 . General 

The tunnel in this instance is the Keystone Tunnel on the Ri- 
chardson Highway near Valdez, Alaska. The tunnel is 600 feet long 
and was originally 12 feet wide with one-lane traffic. In 1950-52 
the tunnel was widened to about 20 feet to accommodate two lanes of 
traffic. The tunnel is basically through rock, but near the north 
end a "chimney" of unconsolidated alluvium was intersected as 
shown in Figure C-4. This chimney section, about 20 feet in length, 
was supported by timber cribbing which covered about 90 feet of the 
tunnel . 

In 1972, the Alaskan Highway Department authorized a feasibi- 
lity study to determine if grouting could be employed to stop water 
leakage into the tunnel and consolidate the alluvium to relieve the 
load on the timber cribbing. 



....■A$t§lB'^ 


/—FINAL BORE 
/ 




w 


V s1 



CHIMNEY OR 
CHUTE 



B 




SECTION "B-B" 



Figure C-4. Tunnel enlargement showing intersected chimney 



213 



2. Discussion of Feasibility Study 

Two problems were pointed out in the feasibility study. These 
problems were: 

a. The rock section of the tunnel was leaking water in 
several areas. Two major leak points created a 
traffic hazard and a maintenance problem. 

b. The unconsolidated chimney section of the tunnel 
was placing excessive loading on the timber crib- 
bing to cause deflection and also was leaking 
badly. 

The study concluded that the leaking rock section could be 
grouted to control the water and that the unconsolidated alluvium 
could be stabilized with chemical grout to ease the load on the 
timber cribbing. It was also recommended that the grouting be 
done during the thaw time so results could be evident. 

3. Job Discussion 



The rock grouting portion of the job will not be discussed 
since it is not pertinent to soils grouting. 

The grout material used was Halliburton's PWG® acryl amide 
grout (AM-9) in a 20% mixture. The grout was placed through 
drive type E-Rod grout points with a pump-open point. 

Preparation for the grouting was made by cutting 2-1/4 inch 
diameter holes in the wooden cribbing on a 2 to 3 foot grid pat- 
tern as shown in Figure C-5. The drive rod grout points were 
driven 15 feet deep into the sand using a modified track drill. 
The point was opened and 100 gallons of grout was pumped into 
the sand with a small air-driven dual plunger pump. Pressure 
at maximum depth was kept below 60 psi at grout point and at 30 
psi from 10 feet depth to surface. 

After each injection of 100 gallons of grout, the drive 
rod was pulled 6 inches toward the surface and injection made 
again. This procedure was repeated until the drive rod was 
retrieved from the sand. The set time for the grout was one to 
two minutes. Injections were made in each row on holes 1 and 3, 
then holes 2 and 4, etc., until the area was completely grouted. 
The grouting was done in 1974. 



214 




Figure C-5. Grout point locations in chimney section 



4. Results 

The chimney section of alluvium was consolidated to a thick- 
ness of 15 to 16 feet thick for 25 or 26 feet in length. The sam- 
ples of grouted alluvium from this area showed a compressive 
strength of over 100 psi. Followup reports show that the conso- 
lidated section is supporting the overburden and has eliminated 
the leakage in that section. 



215 



EXHIBIT D 

CASE HISTORY 

PREGROUTING FOR TUNNELS UNDER 26 RAILROAD TRACKS 
PONTIAC, MICHIGAN 

1 . General 

The need arose to bore a 14 foot diameter and a 4 foot diameter 
sewer tunnel 300 feet in length under 26 tracks in the Grand Trunk 
rail yard at Pontiac, Michigan. It was required that the work be 
done without stopping rail traffic in the rail yard. The contractor, 
Greenfield Construction Company of Livonia, Michigan, investigated 
the possibility of pregrouting the area for excavation of the tun- 
nels to provide support for the rail traffic above during the tunnel 
excavation. 

Core samples indicated that the formations down to a depth of 
12 feet had a high permeability and below this the permeability was 
lower, but still sufficiently high to permit the use of a chemical 
grout for soil consolidation. The porosity varied from 28% at the 
upper edge of the grouted square to 22% at the bottom. 

2. Job Procedure 



When Halliburton Services was approached as the grouting con- 
tractor, they suggested that the large tunnel be pregrouted only 
around the circumference and the interior be left unconsolidated. 
This would accomplish the purpose at much less expense. The smaller 
tunnel would be completely grouted. 

The grid pattern used and the grouted areas are shown in 
Figure C-6. The grout used was Halliburton's Injectrol® G sili- 
cate grout. It was injected through E-Rod drive grout points. The 
grout points were driven to 32 feet in depth, then injection was 
made at each foot for the lower three feet and repeated on 18 more 
feet for the outer two rows in the grid pattern. The three inte- 
rior rows in the pattern were then injected at depths of 11 to 15 
feet on one foot intervals. The small tunnel was injected at each 
foot over the 8 foot depth. Injection started with the grout at a 
low 2 cp viscosity. The rod was moved one foot when the pressure 
rose to approximately 40 psi. 

The equipment for the job is shown in the schematic drawing, 
Figure C-7. The square tanks represent large mixing and holding 
tanks. The small circular tanks marked "A" and "B" represent tne 
55 gallon tanks by each pump where the two fluid components are 
pumped into the ground in equal volumes and mixed together as they 
go into the drive rod grout point. 

216 










WZfrsm/- 



J/ 



^y 



Z< /■ /'- 

K £_^_._£_ y 



fl- 



~*\ymxFn 






WW 



J4«S 



^^^p^S^-^^ST 



:^M- : : 00My j^4W^ 




Figure C-6. Grid pattern and grouted areas 



The entire job consumed about 100,000 gallons of Injectrol G 
grout. Had the large tunnel area been completely grouted, it would 
have required an additional 71,000 gallons of grout. 



217 




s.s. 

CI, 
40 



PO/AP, 



1M 



MIX 



piMP 



41 




S*H5 



LT^CE/ 



ixj-U 




trt-PA^ 



by.pAib 



IZ.EEL 



-w- 



PU/AP 






*j- 




ftY-PAM 



3. Results 



Figure C-7. Schematic equipment layout 



After the completion of the grouting, the large tunnel was mined 
successfully. It was necessary to grout certain parts of the tunnel 
area again as work proceeded. An additional 10,000 gallons were 
used for this purpose. 

The small tunnel was bored successfully without any further 
grouting. 

No settlement was noticed in the railroad tracks during the 
mining process. 



218 



EXHIBIT E 

CASE HISTORY 

GROUTING FOR SEWER LINE SUPPORT NEAR METRO TUNNEL 
WASHINGTON, D.C. 

1 . General 

A large sewer line called the New Jersey Sewer passes over a sec- 
tion where twin tunnels of the Metro System in Washington, D.C. are to 
be located. This is in the Mall area at 7th Street N.W. The general 
construction contractor was Dravo Construction Company. E.C.I. - 
Soletanche of Pittsburgh, Pennsylvania made the investigation and recom- 
mendations for the grouting operation and furnished supervisors to help 
Dravo mix the grouting materials. 

2. Grouting Procedure 

Two 16 foot diameter shafts located 45 feet each side of the sewer 
were dug to a depth of 15 feet. The grout holes were drilled from each 
shaft to a location under the sewer pipe in sufficient width to give 
substantial support over the tunnel section. A schematic of this is 
shown in Figure C-8. The site showing the two shafts is seen in 
Figure C-9. 

The pump rate used for the grouting was 1.5 gpm (300 liters/hr.) 
over an 8 hour shift. The initial grouting was with bentonite cement. 
After 2,200 cubic feet of this slurry had been injected, the balance of 
the grouting was conducted using silicate grout. Twelve thousand cubic 
feet of silicate grout was injected into the sand. The grouting was 
done over a three month period. 

3. Results 



The first one of the two Metro tunnels was bored under the sewer 
line in August 1974. During the boring operation under and in the 
vicinity of the sewer line, no sand was encountered. All the excava- 
tion was in clay. A few stringers of cement were the only visible 
evidence of the grouting. Figure C-10 shows the tunneling in process 
at the site. Figure C-ll is a closeup showing the large pieces of 
clay encountered in the tunnel boring. 

The second tunnel was also found to be entirely in the clay. 
This shows that a more thorough investigation over the site could 
possibly have shown that the grouting was not necessary, resulting 
in a saving of thousands of dollars. The effect of grout on the 
sands above the tunnel was not determined. 



219 







Figure C-8. Schematic of grouting for sewer support. 




Figure C-9. Washington grouting site 
220 




Figure C-10. Typical excavation under grouted area, 




Figure C-ll . Clay encountered in tunnel excavation, 

221 



EXHIBIT F 

CASE HISTORY 

GROUTING OVERPASS PIERS ON ROUTE OF METRO SYSTEM 
WASHINGTON, D.C. 

1 . General 

Two tubes of the Metro system are to pass under the bridge piers 
of the 7th Street overpass of 1-95. The engineers did not want any 
loss of support during excavation to cause settlement of Interstate 
Highway 1-95 or of the piers which support the overpass. The grout- 
ing was completed and tunnels have been bored. The grouting contrac- 
tor was Hayward Baker Company. 

2. Job Information 

The work was done where 7th Street passes on grade over 1-95. 
There is a column on each side of 1-95 and in the median which sup- 
ports the overpass bridge, with 1-95 being four-lane in each direc- 
tion. The subway tunnel was excavated under 7th Street and passed 
underneath the three piers and 1-95. 

The grouted section extends 20 feet beyond the two extreme 
piers on the outside of 1-95 and the complete section under the 
highway. It includes approximately the total width of 1-95 plus 
40 feet to take care of the outside dimensions. 

The grouting pattern at the highway level called for drilling 
the hole approximately 17 feet deep with a stabilator-type drill. 
The casing was carried down as the hole was made with the drill rod 
and the eccentric bit extending beneath the casing. After the total 
depth was reached, the bit was knocked off and a 1-1/2 inch polyethy- 
lene pipe with slots sawed in the bottom 7-1/2 feet was placed inside 
this 3-1/2 inch casing. After this plastic pipe was placed, the 
annul us between this pipe and the casing was filled with ordinary 
masonry sand up 7-1/2 feet. Then the casing was pulled to this 7-1/2 
foot level, and cement grout mixed with sodium silicate was placed in 
the annulus from the 7-1/2 foot level to surface. The casing was 
then withdrawn before the grout set. All grout pipes were set in 
this manner. (See Figure C-12). 

Grouting was done on the surface of the highway with the holes 
drilled on a 7 foot grid pattern. All of the holes in the area of 
the underpass were drilled and grouted; then the 5 spot hole pattern 
was drilled on the inside of the 7 foot pattern and secondarily 
grouted. The idea was for the original holes to give solidification 
and reduce permeability and the inside pattern hole to then com- 
pletely fill the voids and solidify the material. 

222 



iteel Traffic Cap 



a a >-> Pavement -C*? 



1|" PUT Class 200 Pipe 




Figure C-12. Detail of grout pipe installation and seal 



223 



The grouted section was approximately 3-1/2 feet each side of the 
crest line of the tunnel; i.e., the material 3-1/2 feet above the top 
of the tunnel and 3-1/2 feet into the tunnel will be grouted throughout 
the length of this section. 

The grout hoses were fastened to the top of the grout pipe and ap- 
proximately 900 to 1000 gallons of grout were injected in this pipe and 
forced out through the sawed slots in an attempt to distribute grout 
throughout the sand and consolidate the sand. 

The chemical grout solution was a sodium silicate base with or- 
ganic reactants, modified with oxidizers. The grouting contractor had 
storage tanks on the surface in a vacant lot on the 7th Street eleva- 
tion where he stored the basic materials. None of the materials were 
premixed. One 4 inch Moyno pump was connected to the fresh water line. 
Another Moyno pump the same size was connected to the sodium silicate 
storage tank. 

The pumps had inidivdual water meters in order to control the 
volume injected, but approximately equal volumes are pumped. The 
pumps and meter are shown in Figure C-13. 




Figure C-13. Grout injection pumps and flowmeters 

224 



A schematic of the pump layout is shown in Figure C-14. The 
water and the sodium silicate were brought into one line. Adjacent 
to that was a 2-1/2 or 3 inch Moyno pump which was tied into the 
reactant material. This was ethyl acetate and formamide*, which 
were mixed together and then pumped. Adjacent to that was a 1-1/2 
inch Moyno pump which was piped to the peroxyde oxydizer solution. 
This Moyno pumped the peroxyde into the flow stream of ethyl ace- 
tate and formamide solution and mixed them together. The dis- 
charge from these pumps and the discharge from the water-silicate 
pumps came together in a 2 inch rubber hose further down the line. 
This then became one solution which was pumped across and down to 
the underpass to a manifold with 8 connections, as shown in Figure 
C-15. This manifold had flowmeters on each line with a one inch 
hose leading out to be connected to groutpipes in the holes. They 
attempted to get 60 to 80 gallons per minute of total flow with 
6 or 8 gallons per minute going into each of the individual grout 
holes. 

The maximum injection pressure at the grouthead of each of 
the individual grout pipes was 25 pounds per square inch, but very 
few of the grout holes showed much indication of pressure buildup, 
so apparently the material was going readily into the sand. 

During a period of grouting near the ground surface, grout 
was observed on the surface around the curb and in the service 
manholes of the underpass. This was not noticed, however, during 
the majority of the grouting operation. After the primary holes 
on the injection pattern were grouted, about 80% of the secondary 
holes showed indication of reduced permeability as they took 
smaller amounts of grout and the pressure rose quickly during 
grouting. 

Attempts were made to determine the strength of the grouted 
soil using a Menard pressuremeter, but results were inconclusive. 
A 36-inch diameter hole was drilled through the grouted section 
to the top of the clay. The wall "stood up" without casing or 
other support, so that the section could be observed from a ladder. 
It was found that the grout had consolidated the soil, but samples 
large enough for testing were not obtained. 

Two 20-foot diameter tunnels have been dug, but both were 
under the grouted area in cohesive soil. Two additional tunnels 
are being dug at this writing, which will pass through the grouted 
area and very close to the overpass piers. 



* Patented process by Hayward Baker Company, 

225 



Water 



Variable Speed 
Transmissions 
to each Pump 




Reactants 



Compressor 




J 



O 



multiple 
Grout Hoses 
to Grout Pipes 



Air Line 
to Drill 



Water Flushinn Lines 



Figure C-14. Schematic - pumping system. 
226 



GROUT SUPPLY 




41 1 51 |6r~~17 



ri 



s 



7'KJ 



7' 







] FLOWMETER 




Figure C-15. Schematic - grouting manifold, 
227 



EXHIBIT G 

CASE HISTORY 

GROUT CURTAIN ON EARTHEN DAM 
PUBLIC SERVICE COMPANY OF OKLAHOMA RESERVOIR #13 
WASHITA, OKLAHOMA 

1 . General 

An earthen dam was constructed in 1956-1957 across Leeper 
Creek. The natural grade of the terrain at the center line of the 
dam ranges from 1220 feet to 1275 feet. The top of the dam is at 
1310 feet, with water level at 1280 feet. The length of the dam is 
approximately 2000 feet. 

Leakage below the dam created swampy conditions on adjoining 
property, and also aroused fears that "piping" might jeopardize the 
integrity of the structure. A clay blanket, applied to the up- 
stream side of the dam, resulted in reduced leakage at the west end, 
but appeared to have little effect on the leakage near the creek bed. 

Test borings and data from drawdown pumping tests indicated 
that the entire area immediately under the dam fill from about 100 
to 150 feet east of the creek bed and west for a distance of about 
900 feet, consists of quicksand and stratified layers of permeable 
sandstone and sand, saturated with water which is migrating to the 
meadow immediately downstream from the dam. 

It was concluded that two conditions existed: 

a. A considerable volume of water from the reservoir was 
flowing through the 20 to 30 foot thick formation 
immediately below the compacted fill forming the dam. 

b. The formation immediately beneath the dam fill was 
unstable, with poor bearing capacity to support the 
weight of the dam fill material. 

2. Grouting Operations 

Based on the boring and drawdown test data, a series of grout 
holes were drilled from a road made on the upstream slope of the 
dam at 1292 feet elevation, in a straight line on the inner slope 
of the dam, about 12 feet above the water line. The holes were 
drilled 5 feet apart, starting at a point 420 feet west of the east 
end of the dam, for 260 feet to a point 680 feet from the east end 
of the dam. Each hole was drilled to a depth of approximately 20 
feet below the elevation of the dam fill material. Each hole was 
cased with two inch pipe to bottom, and grouted in place. This 
layout is shown in Figure C-16. 

228 



n 



GROUT HOLES O O 

TEST HOLES + 



2 r 

2 



n 

- 2 

T 



»* 



DETAIL OF GROUT AND TEST HOLES 




ROAD ON SLOPE OF DAM STA. 680 ••.•.••.••■■.••.•■• ST A. 420 



^^- 4. CREST TEST HOLES 
#9 #7 *8 



\ ' ' » ■ I ' ' ' ' | 1 l 

200 400 800 

SCALE: 1"=400' 



1 

1200 



Figure C-16. View of grouting area on dam. 
229 



Grouting was accomplished with Injectrol® G silicate grout with 
a set time of 30 minutes. Each hole was grouted in five- foot stages, 
starting at the upper stage and working down. The upper stage was 
the interval immediately below the dam fill. The pipe interval in 
each five- foot stage was perforated first before grouting with one 
perforation per foot, for a total of five perforations per stage. 
Each of the top three stages were grouted with 250 gallons of 
Injectrol G grout and each bottom stage with 300 gallons. 

The general pattern of grouting was to grout alternate holes 
(10' O.C.) one day, and the intervening holes the next day. 

The holes east of the center of the treatment area were grouted 
during the first eleven work days, and the holes west of center dur- 
ing the last eight work days. 

The highest initial pump pressure during the job was 60 psig 
in the first stage in hole number 475. The lowest pump pressure 
recorded was 10 psig. Average pump rate was approximately 10 gpm. 

Grouting equipment used included one mixing unit, one van, one 
AC pump unit and one hose reel. 

The maximum number of personnel on the job at any time were 
2 engineers, one grout operator and four helpers. 

After mixing and pumping 1,000 gallons of Injectrol G silicate 
grout the first day, an average of 3,080 gallons per day was in- 
jected during the remaining 18 work days. A total of 56,650 gallons 
of grout was used. 

Treatment depth varied from 40 to 60 feet (elevation 1252' to 
1232') at east holes and 65 to 92 feet in center portion back to 
54 to 74 feet at west end of treatment area. This variation fol- 
lowed the profile of the dam taken 90 feet upstream from center 
line of dam. 

3. Job Results 



An investigation was undertaken about four months later to 
determine the effectiveness of the grouting job done during 
September 1968. 

Nine 4-1/2 inch holes were drilled for the field testing. A 
two-inch pipe, with the lower ten feet slotted and covered with 
screen wire, was put into the hole. The intervals tested in each 
hole were (1) a ten-foot interval above the grouted interval, (2) 
the upper ten-foot grouted interval (3) the lower ten-foot grouted 
interval, and (4) a ten-foot interval immediately below the grouted 
intervals. 



230 



The depth and location of the test holes are tabulated in Table 
C-2 below. The term "Station No." refers to the distance of the hole 
in feet west of the east end of the dam. 

TABLE C-2 
HOLE DRILLING SCHEDULE 



Hole 
No. 


Station 
No. 


Total 
Depth 

93 


Note 
On Depth 


1 


572.0 




2 


627.0 


90 




3 


517.5 


82 




4 


542.5 


86 




5 


557.5 


91 




6 


612.5 


60 




7 


465.0 


100 


2 


8 


390.0 


80 


2 


9 


540.0 


97 


2 


Note 1 - 
Note 2 - 


From road 
Elevation 
From cresl 
Elevation 


for grout 
1292' 

; of dam - 
1310' 


curtain - 



Holes 1 and 2 in line with the grout holes were drilled with 
mud and left standing full while other holes were drilled and tests 
made. Cores were taken in Hole number 1 (Station 572) from 61 feet 
to 93 feet and in Hole number 2 (Station 627) from 58 feet to 90 
feet. Holes were 2 feet from one grout hole. 

Compressive strength tests were made of two cores taken from 
Hole number 1 which was grouted from 67-87 feet. A core 7/8-inch 
in diameter and 1-1/2 inches long was taken from 61 feet depth. It 
showed a strength of 2.44 psi or 351 psf. A core 3/4-inch in dia- 
meter and 1-1/2 inches long taken at 67-1/2 feet showed a strength 
of 31.7 psi or 4564 psf. The marked difference in strength indicates 
that the grouting increased the strength greatly. 

231 



This conclusion is confirmed by the flow tests made through 
two cores from the same locations as shown in Table C-3 and from 
water immersion tests shown in Table C-4. 









TABLE C- 


-3 










FLOW RATE 


TEST 




Station 

No. 


Depth 
(Ft) 

61 


Core 
Diameter 
(In) 

3/4 


Size 
Length 
(In) 

1% 


Fluid Flow 
cc/min 

2.16 


Differential 
Pressure 
psig 


572 


2 


572 


67% 


3/4 


1 





800* 



*The Hassler Sleeve, rubber core holder, burst and damaged the 
core. 









TABLE C-4 








IMMERSION TEST 




Station 
No. 


Depth 
(Ft) 

61 


Sample Weight 
Approximately 

200 grams 


Physical State 
Before Immersion 

One piece 


Physical State 
After Immersion 


572 


Loose sand 


572 


67% 


150 grams 


One piece 


One piece 



The cores from above the grouted section were unconsolidated as 
expected. The cores in the upper and lower parts of the grouted sec- 
tion were consolidated in Station No. 572, but the center section was 
unconsolidated. This indicated that the grout from adjoining holes 
did not completely overlap, leaving a portion unconsolidated. The 
same explanation was true for the center and lower part of Station 
No. 627. This indicated that the holes should have been closer to- 
gether or more grout injected through each hole. The visual tests 
shown in Table C-5 also confirmed the above explanation. 

Tests were then made in Holes 7, 8 and 9 on the top of the dam 
using an electric probe to measure the depth of water in the hole. 
These holes were downstream from the grout curtain. 

Hole number 7 (Station 465) was drilled with air to a depth of 
100 feet, but a satisfactory test could not be obtained due to plug- 
ging of the pipe with flowing sand. 

232 



TABLE C-5 
VISUAL INSPECTION TEST 

















Station 


Depth 


Sect 


ion 


Length of 


Core 




No. 


(Ft) 
61 


Grou 
67' 


ted 
- 87' 


Recovered 
10 


(In) 


Appearance 


572 


Unconsolidated 


572 


67*2 






11 




Consolidated 


572 


72 






14 




Unconsolidated 


572 


87 






15% 




Consolidated 


572 


93 






14 




Top partially conso- 
lidated, bottom 
unconsolidated 


627 


58 












627 


58 


64% 


- 84% 


11 




Consolidated 


627 


64ig 






13% 




Consolidated 


627 


74 






15 




Partially consoli- 
dated 


627 


87% 






12 




Unconsolidated 


627 


90 






12% 




Top partially conso- 
lidated, bottom 
unconsolidated 



Hole number 8 (Station 390) was drilled with air 30 feet east of 
the east end of the grout curtain to a depth of 80 feet. Water was 
being blown out at about 59 gpm at the 80 foot depth. The head of 
water built up 30 feet in 15 minutes to an elevation of 1260 feet. 

Hole number 9 (Station 540) was drilled with air to a depth of 
97 feet. The two- inch pipe was hung at 90 feet, but water head build- 
up was measured at 62 feet (elevation 1248 feet) in one hour and 52 
feet (elevation 1258 feet) in 2 hours. 

Holes 3 through 6 were drilled halfway between grout holes and 
2-1/2 feet towards the downstream side of the dam. Table C-2 shows 
hole location by station number and depth of hole. The hole was 
4-1/2 inches in diameter. Testing was accomplished in the following 
manner: The hole was drilled to the top of grouted section and tests 
made in the lower 10-foot section. Then the hole was drilled 10 feet 
into the grouted section and tested again. The hole was drilled 
another 10 feet into the grouted section and tested and then drilled 
10 feet below the grouted section and tested again. 

The test was conducted using the air bubble method. In this 
test, a 3/4-inch flexible hose was lowered inside the 2-inch pipe 
through a packing at the surface, blowing the water or mud from the 
hole as it was lowered. Air continued to blow the hole free of 

233 



water until only a mist was obtained. The air flow was then reduced 
until it was very low. The air line at surface was connected to a 
continual source of air and a strip-chart pressure recorder which 
recorded the air pressure. As the water began to fill the hole, the 
pressure of the air had to increase in order to overcome the water 
head. This pressure can be read on the recorder as a function of 
time to obtain the head of water in the hole. 

Results of tests made in Holes 3 through 6 by air bubble method 
are shown in Table C-6. It can be noted that the tests do indicate 
that the grouting was successful in reducing or eliminating the water 
flow in the area grouted. 

TABLE C-6 

TESTS OF GROUTED AREA OF DAM 





















Total 








30-Minute 


Hole 


Station 


Depth 


Grouted Interval 


Test 


Interval 


Fill up 


No. 


No. 


(Ft) 
82 


Depth (Ft) 


(Ft 


(Ft-Water) 


3 


517.5 


52 - 72 





- 52 













52 


- 62 













62 


- 72 













72 


- 82 





4 


542.5 


86 


56 - 77 



56 
66 
76 


- 56 

- 66 

- 76 

- 86 








20 


5 


557.5 


91 


63 - 83 



61.5 
71.5 
81.5 


- 61.5 

- 71.5 
-81.5 

- 91.0 






44* 





6 612.5 60 Air drilled. Moisture at 60' prevented 

further drilling. Moisture had migrated 

___^^ from nearby holes. 

*Fell to 35 feet in next 30 minutes 

Conclusions 



Although the grout curtain was not placed all the way across the 
dam, it did span the center portion over the existing creek bed. This 
grout curtain of Injectrol® G silicate grout reduced the flow of water 
through the dam over 90% in the area of the grout curtain. 

Some sections of the grout curtain show to be unconsolidated. 
This is probably due to the grout from adjoining holes not overlapp- 
ing, leaving gaps through which water can leak. Only one row of 

234 



grout holes was used. Completely sealing the leakage would require 
another row of holes or injection of more grout in the present holes 
It is doubtful if the additional results would justify the expense. 

Hole number 8 drilled to the east of the grout curtain at Sta- 
tion 390 indicated that a flow of water was still going through the 
dam around the east end of the grout curtain, but sufficient grout- 
ing was done to prevent damage to the dam. 



235 



EXHIBIT H 



CASE HISTORY 



SOIL CONSOLIDATION FOR TUNNEL EXCAVATION 
WASHINGTON, D.C. METRO SYSTEM 

1 . General 

This grouting was done by the Hayward Baker Company with the 
same materials and technique used on the 1-95 overpass grouting re- 
ported in Case History F. 

2. Job Information 



This work was in connection with the mining of a tunnel for the 
Washington Metro located near RFK Stadium. The construction company 
had encountered sand and gravel along with an inflow of water. This 
was causing the face to "run", which resulted in an extension to the 
surface of the ground where settlement occurred. To stop this condi- 
tion, grouting was considered and selected for the application. 

The procedure for grouting was the same as used for the grouting 
under the piers of the 7th Street overpass on 1-95. The holes were 
drilled and cased on ten-foot centers on a three-row grid pattern to 
a depth varying from 50 to 60 feet. A 1-1/2-inch plastic pipe, with 
the lower tqn-foot section slotted at given intervals, was placed 
inside the casing and the lower ten feet surrounded with small gra- 
vel. The casing was then pulled up ten feet to the top of the sand. 
A light grout of cement and silicate was placed around the annulus 
from the sand pack to the surface, and then the casing was withdrawn 
from the hole before the grout set. 

Figure C-17 shows the site above the tunnel, looking in the di- 
rection of the tunnel. The face of the tunnel is behind and below 
the observer. Three rows of plastic injection pipes are in the 
center of the picture. The two drilling rigs, a small mixer for 
the sleeve grout, and the grouting trailer are evident in the fore- 
ground. 

Figure C-18 shows the grout distribution manifold. The large 
pipe on the left brings the grout to the manifold. The grout can 
be divided among the 6 smaller pipes of the manifold, where a line 
from each has a hose going to one of the plastic injection pipes 
set in the ground. Pressure gauges on each line were used to try 
to equalize the flow through all lines and indicate the actual 
injection pressure at the surface. There are valves on each line 
so the number of lines actually connected and being used can vary 
from one to six. Apparently five lines were being used at the 
time the picture was made. Flow indicators were also used on 
each line. 

236 







Figure C-17. Grouting site. 




Figure C-18. Grout distribution manifold, 



237 



Figure C-19 shows grouting operations approaching the open cut 
section of the tunnel. The tunnel is progressing toward the large 
portal opening supported with soldier beam and lagging walls. Figure 
C-20 is the lower portion of the portal. Groundwater, along with 
grout fluid, can be seen in the lower left issuing through the wall 
as the grout fills the pores in the sand to be mined. 

Figure C-21 is a view of the sediments at the face of the tun- 
nel beneath the shield. The soil was very stable and dry. The con- 
solidation seemed to be uniformly distributed, and mining was accom- 
plished without any further problems. 

Figure C-22 is a photograph of a sample of consolidated mate- 
rial taken from the face of the tunnel during mining. This sample 
was kept in an air-tight plastic sack to prevent drying. Two test 
pieces were obtained from the large sample. The unconfined com- 
pressive strengths of the samples were 32 psi and 44 psi, or an 
average of 38 psi. The presence of the large gravel and a wide 
range of particle size tends to make the compressive strength lower 
than if the soil were finely graded. 

The silicate in the grout probably varied from 45 to 50 per- 
cent of the grout fluid, and the contractor injected about 30 
percent by volume of chemical grout to the volume of the sand being 
grouted. 

3. Results 



The first tunnel was mined behind the grouting. The soil was 
stabilized sufficiently to permit excavation without further loss 
of sand, so the contractor decided to reduce the silicate concen- 
tration to about half of that used in the first tunnel. The second 
tunnel was grouted using about 25% sodium silicate concentration, 
and it was then mined out without any trouble. 

When trouble was encountered with running ground, the tunnel 
contractor was able to dig only 30 feet of tunnel in 30 days. After 
grouting, the tunnel was dug at the rate of 30 feet per day. 



238 




Figure C-19. Grouting toward portal opening 




Figure C-20. Tunnel portal opening. 
239 




Figure C-21. Grouted soil at tunnel face, 





Figure C-22. Sample of grouted soil 
240 



D. Testing Information 

1. In Situ Permeability Test Procedure 

An in situ test procedure using a piezometer is an economical 
method which can be used in a wide range of soil types. This pro- 
cedure is based on work by the Corps of Engineers (Hvorslev, M. L., 
Ref. 69) and by William G. Weber, Jr. ("In Situ Permeabilities for 
Determining Rates of Consolidation," State of California, Transpor- 
tation Agency, Department of Public Works, Division of Highways, 
Highway Research Board Meeting, January 1968). 

The test is performed using non-metallic, porous tube type 
piezometers. The piezometers consist of the porous stone permea- 
meter with or without sand filter, placed in the soil mass. The 
permeameter is normally 1-1/2 inches in diameter and either 1 or 
2 feet long. A 1/2 inch plastic tube is connected to the porous 
stone and extends vertically to the ground surface. A schematic 
of the piezometer installation is shown in Figure D-l. The test is 
normally conducted using the open type system, however, it can be 
conducted using the closed type system. 

In conducting the test using the open piezometer system, the 
water level in the plastic tubing is lowered about 5 feet. This is 
accomplished by means of a hand vacuum pump connected to a 1/4 inch 
plastic tube placed inside the 1/2 inch plastic tubing. The end of 
the 1/4 inch plastic tubing is at the depth of the desired lowering 
of the water level. The depth to the water level is then measured 
at various time intervals, see Figure D-2 The pressure head at a 
given time interval is then divided by the amount of the total re- 
duction in head. The time interval is plotted against the logarithm 
of the head ratio. A typical example of the field data are shown in 
Figure D-3. From these data the basic time lag, the time for H/H 
to equal 0.37, is determined. 

It may be noted that these time lag curves do not always form 
a straight line through the zero time where H/H equals 1.00. This 
is primarily due to air in the soil or piezometer system. By lower- 
ing the water level in the 1/2 inch plastic tubing, the pressure is 
reduced and the air expands, partially escaping. This is one of the 
reasons for the use of the rising head test instead of the falling 
head test, where water is introduced into the system to increase the 
head. The correction for the air is made by parallel shifting the 
straight line portion so as to pass through the zero time where H/H 
equals 1.00. This parallel shifting of the curve assumes that the 
air has not affected the volume of water passing through the porous 
stone, which is only approximately true when small amounts of air 
are present. This restricts the use of this test to saturated soil. 

These time lag curves are the basis for calculating the permeabi- 
lity of the soil surrrounding the piezometer. There are three physi- 
cal dimensions that are required to be known to calculate the 

241 



UNCASED 
OPEN SYSTEM 



CASED 
OPEN SYSTEM 



UNCASED 
CLOSED SYSTEM 



S/2 M Plastic 
Tubing 





Pressure 
Gage 



Porous 
Stone 



5*2^^3^^ g ^ »gfe * ffi 




Seal 



Sand 



i 



&m 



Figure D-l . Piezometer installations (schematic). 

242 



Stable free 
water 



or piezometric 
level 



Ground Surface 



H 



H 



H 



H, 



t=0 



1/2" Plastic Tubing 



■Porus Media 



Figure D-2. Piezometer test - falling head, 



243 



LAFAYETTE B 
PERM. NO. 



FIRM SILTY CLAY 
O Run No. 
X Run No. 2 




LENGTH PERM. 2.0 FT. 

JETER PERM. 0.20 FT. 
FIELD K = 2.2 x I0~ 3 ft/hr 



J... 



JL 



10 



TIME 



HOURS 



Figure D-3. Typical field time lag curve. 

permeability: the length of the permeameter, the diameter of the 
permeameter, and the diameter of the stand pipe. These variables 
can all be measured with reasonable accuracy. Using the following 
equation., the permeability can be calculated. 



Where: 



K h 
a 

L 

d 

In 

m 




(78) 



Permeability in the horizontal direction 

Area of standpipe 

Length of permeameter 

Diameter of permeameter 

Natural logarithm 

Square root of the ratio of horizontal 

to vertical permeabilities 

(assume m = 1 for 1st approximation) 

Basic Time Lag 



244 



2. Laboratory Grout Distribution Tests 

Tests were conducted in the laboratories of Halliburton Ser- 
vices, Duncan, Oklahoma to attempt to determine if the distribution 
of grout could be monitored during the injection. A test box con- 
taining saturated medium fine sand was used for the tests. A single 
grout injection pipe was placed in the center of the box as shown in 
Figure D-4. 

The grout distribution was traced by electrical surface measure- 
ments in the laboratory. At least three "four-electrode" systems 
were used in the tests. Each four-electrode system is comprised of 
two current electrodes between the grout hole and the current elec- 
trode. Figure D-5 shows the layout of four of the four-electrode 
systems. A fracture was simulated by placing a thin layer of coarse 
sand in the test box. An acryl amide grout mixed with 10% salt water 
was injected. The grout followed the "fracture", and the resistivity 
measurements indicated the direction the grout traveled. 

A later test indicated that the first part of the injection fol- 
lowed the simulated fracture i then, after filling the fracture, the 
grout spread out fairly evenly across the test box. Observations 
after the set grout was dug out corroborated this. 

A patent covering this monitoring technique is attached. 




Figure D-4. Equipment for laboratory grout distribution test. 

245 



4 ELECTRODE SYSTEM PLACEMENT 




6 
I 



Figure D-5. Test probe layout. 



246 



May 9, 1967 c. d. mcdoulett etal 3,319,158 

METHOD OF TRACING GROUT IN EARTH FORMATIONS BY MEASURING 

POTENTIAL DIFFERENCES IN THE EARTH BEFORE AND 

AFTER INTRODUCTION OF THE GROUT 

Filed July 9. 1964 



-ee 






t£ 'o 



J.C. 






fix _a* &7&V7Z46 




CUBBGW 




cueegwr 

set/sec* 







& 



/V77FA/r/ste 






J*T&.\0. 



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.FX&'t £, 



coeeavr 



Y(»X) 




£Z£Z"7ZZ>/? l £'^*(5zt 



/NVENTOR5. 



BY *f* ^Z^ 



247 



United States Patent Office 



3,319,158 

Patented May 9, 1967 



3 319 158 
METHOD OF TRACING GROUT IN EARTH FOR- 
MATIONS BY MEASURING POTENTIAL DIFFER- 
ENCES IN THE EARTH BEFORE AND AFTER IN- 
TRODUCTION OF THE GROUT 
Claude D. McDoulett and Marvin C. Tucker, Duncan, 
Okla., assignors to Halliburton Company, Duncan, 
Okla., a corporation of Delaware 

Filed July 9, 1964, Ser. No. 381,473 
3 Claims. (CI. 324 — 9) 

This invention relates to a method and system for 
determining the distribution of grout around an injection 
well. 

When injecting grout through a pipe into an earth for- 
mation, it is desirable to trace the relative distribution of 
grout around the pipe while it is being injected into the 
formation. Various methods of grout tracing and elec- 
trical systems for carrying them out have been proposed. 
The most common such system presently in use consists 
of a plurality of four electrode systems distributed about 
the grout hole in a predetermined pattern. Each of the 
four electrode systems comprises a pair of current elec- 
trodes spaced relatively distant from the grout hole on 
opposite sides thereof and a pair of potential electrodes 
aligned with the current electrodes and the grout hole 
and positioned considerably closer to the grout hole than 
the current electrodes. 

A constant A.C. current is supplied to the current elec- 
trodes and an A.C. millivolt meter is connected to the 
potential electrodes. Generally, three such four-electrode 
systems are required to adequately cover the 360° around 
the grout pipe. Such a system requires sixteen lead cables 
and electrodes, and satisfactory operation is obtained only 
by spacing the current electrodes at least forty feet from 
the grout pipe. 

Since it is often necessary to carry out a grouting oper- 
ation within narrow confines, a conventional four-elec- 
trode system is frequently not usable, at least in its most 
accurate manner. Moreover, it is often difficult, as well 
as uneconomical, to transport the number of cables of the 
length required to the site of the grouting operation. It 
has also been found that the sensitivity of the four- 
electrode system is quite low and requires a substantial 
resistivity contrast between the grout and the formation 
fluid before meaningful results can be obtained. 

It is therefore an object of the present invention to 
provide a system for tracing the distribution of grout 
around a grouting hole that requires less equipment and 
can be set up in a smaller area than has heretofore been 
possible. 

It is also an object of the present invention to provide 
such a system in which only one electrode need be spaced 
a substantial distance from the grout hole and in which 
the grout pipe itself is used as an electrode. 

It is another object of the present invention to provide 
such a system which is extremely sensitive and whicn per- 
mits the use of grout having a resistivity relatively close 
to that of the formation fluid. 

It is a still further object of the present invention to 
provide an improved method for tracing the distribution 
of grout around a grout hole. 

These and other objects and advantages of the present 
invention will become more apparent upon reference to 
the accompanying description and drawings in which: 

FIGURE 1 is a diagrammatic plan view showing the 
disposition of the electrodes of the system of the present 
invention; 

FIGURE 2 is a diagrammatic representation of the 
system of the present invention; and 

FIGURE 3 is a schematic diagram of the electrical sys- 
tem of the present invention. 

Referring now to FIGURE 1, a grout pipe 10 is shown 



surrounded by a plurality of electrodes 12, 14, 16 and 18 
which serve as potential electrodes in the system of the 
present invention. These electrodes are preferably angu- 
larly spaced at 90° intervals around the grout pipe and 
5 are spaced from the grout pipe by a distance X. A fur- 
ther electrode 20 is spaced from the grout pipe 10 by a 
distance Y which is much greater than the distance X. 
The electrode 20 serves as a current reference electrode 
in the circuit while the grout pipe 10 itself serves as the 

10 common potential and current electrode of the system. 
As can be seen in FIGURES 2 and 3, the grout pipe 10 
is connected to one terminal of a source 22 of constant 
A.C. current. The other terminal of the source 22 is con- 
nected through an ammeter 24 to the current reference 

15 electrode 20. The grout pipe 10 is also connected to one 
terminal of a millivolt meter 26. the other terminal of 
which may be connected to any of the potential electrodes 
12, 14. 16 and 18 by means of the movable arm 28 of 
a switch 30 which selectively engages contacts coupled by 

20 cables 32, 34, 36 and 38 to the potential electrodes. 

After the system has been set up, an A.C. current con- 
trolled at a predetermined constant value is applied to the 
combination current and potential reference electrode 10 
and the current reference electrode 20 and passed through 

25 the earth formation between them. The current in the 
formation creates a potential difference between the elec- 
trode 10 and the potential electrodes 12, 14, 16 and 18 
spaced around the electrode or grout pipe 10. 

By means of the switch 30, base readings are obtained 

30 and recorded from each of the four electrodes 12, 14, 16 
and 18 prior to injecting grout into the zone to be con- 
solidated. In most cases, the grout will be more conduc- 
tive than the formation fluid and in such cases the milli- 
volt readings between the electrodes as indicated by the 

35 millivolt meter 26 will decrease as the grout displaces 
the formation fluid in the zone being consolidated. Since 
these readings are taken between the grout pipe in the 
center of the system and the potential electrode spaced 
equally around it, the change in readings per pair of 

40 electrodes will indicate the direction and magnitude of 
travel of the grout. This signal can be read and recorded 
manually or can be continuously recorded by a series of 
suitable recorders. 

In a test of the system described above, the potential 

45 electrodes 12, 14, 16 and 18 were spaced 8 ft. from the 
grout pipe 10 and the current reference electrode 20 was 
spaced 160 ft. from the grout pipe. Before the grout 
injection was begun, a constant A.C. current of 1 amp was 
passed through the formation between the electrodes 10 

50 and 20 and the potentials at the various electrodes 12, 14, 
16 and 18 were measured at 305, 300, 310 and 310 milli- 
volts, respectively. The formation fluid was determined 
to have a resistivity of 5 ohm-meters and the grout, which 
was of the type disclosed in assignee's copending appli- 

55 cation Ser. No. 187,951, filed Apr. 16, 1962, now Patent 
No. 3,223,163, was determined to have a resistivity of 1.58 
ohm-meters. The grout injection depth was 35.6 ft. to 
39.0 ft. It was determined theoretically before the grout 
was injected that 60 gallons of grout would be necessary 

60 to form a consolidated cylinder 4.5 ft. in diameter through 
the sand in the formation. 

After the sixty gallons of grout were injected, the poten- 
tial at electrode 12 had been reduced to 292 millivolts, 
at electrode 14 to 282 millivolts, at electrode 16 to 297 
millivolts and at electrode 18 to 298 millivolts. The total 
change was thus 56 millivolts with 23.2 percent occurring 
at electrode 12, 32.2 percent occurring at electrode 14, 
23.2 percent occurring at electrode 16 and 21.4 percent 

at electrode 18. From these values it can be calculated 
that the grout extends 2.1 ft. from grout pipe 10 towards 
potential electrode 12, 2.56 ft. towards potential electrode 



65 



248 



3,3 



12, 2.18 ft. towards potential electrode 16, and 2.08 ft. 
towards potential electrode 18. 

From the foregoing description, it can be seen that a 
system and method have been provided for tracing the dis- 
tribution of grout around a grout injection pipe. The 
system permits the use of fewer components than has 
heretofore been possible and provides a higher sensitivity, 
thus allowing the use of a grout having a resistivity rela- 
tively close to that of the formation fluid. 

While the system has been described solely in terms of 
determining grout distribution, it should be obvious to 
those skilled in the art that it could also be used to deter- 
mine the extent of other changes in resistivity taking place 
about a given reference electrode, or to determine the 
distribution of other substances, for example, a fracturing 
fluid, introduced into an earth formation. It should also 
be obvious that more or less potential electrodes may be 
used if circumstances warrant. 

The invention may be embodied in other specific forms 
not departing from the spirit or central characteristics 
thereof. The present embodiment is therefore to be con- 
sidered in all respects as illustrative and not restrictive, the 
scope of the invention being indicated by the appended 
claims rather than by the foregoing description, and all 
changes which come within the meaning and range of 
equivalency of the claims are therefore intended to be 
embraced therein. 

We claim: 

1. A method of determining the distribution of a sub- 
stance introduced into an earth formation having a resis- 
tivity different from that of said substance, comprising: 
passing a constant current through said earth formation 
between the point of substance introduction and a point 
remote from said introduction point, measuring the poten- 
tial difference between said introduction point and a point 
much closer to said introduction point than to said remote 
point, introducing said substance into the earth formation, 
and again measuring the potential difference between said 
introduction point and said closer point. 

2. A method of determining the distribution of a sub- 
stance introduced into an earth formation having a resis- 
tivity different from that of said substance, comprising: 



19,158 

4 

passing a constant alternating current through said earth 
formation between the point of substance introduction 
and a point remote from said introduction point, measur- 
ing the potential difference between said introduction 
"p point and each of a plurality of other points spaced around 
said introduction point and positioned much closer to 
said introduction point than to said remote point, intro- 
ducing said substance into the earth formation, and again 
measuring the potential difference between said introduc- 
ed tion point and said spaced points. 

3. A method for tracing the distribution of grout in- 
troduced through a grout pipe into an earth formation 
having a resistivity different from that of the earth for- 
mation, comprising: passing a constant alternating cur- 
io rent through said earth formation between said grout pipe 
and a point remote from said grout pipe, measuring the 
potential difference between said grout pipe and each of 
a plurality of points equally spaced from said grout pipe 
and covering 360° around said grout pipe, said spaced 
20 points being positioned much closer to said grout pipe 
than to said remote point, introducing a known amount 
of grout into said formation through said pipe, and 
again measuring the potential difference between said 
nrout pine and said spaced points, the change in voltage 
2.") between said second readings and said first readings in- 
dicating the distance the grout has traveled through said 
formation toward each of said spaced points. 

References Cited by the Examiner 

30 UNITED STATES PATENTS 

2,181,601 11/1939 Jakosky 324 — 1 X 

2,192,404 3/1940 Jakosky 324 — 64 X 

2,211,124 8/1940 Jakosky 324 — 1 X 

2,440,693 5/1948 Lee 32^_1 

2,459,196 1/1949 Stewart 324 — 1 

2,575,349 11/1951 Lee 324—1 

2,625,374 1/1953 Neuman 324 — 10 X 

3,134,941 5/1964 Norelius 324 — 1 

40 WALTER L. CARLSON, Primary Examiner. 
G. R. STRECKER, Assistant Examiner. 



249 



E. Sample Specifications 

A copy of the specifications for the 1975 grouting job at 7th 
Street and 1-95 in Washington, D. C. is attached. Specifications 
for grouting are not widely used in the United States, so this 
sample is included for information purposes only. Suggested spe- 
cifications are included in a separate design manual, FHWA-RD-76-27. 

The technology of slurry trenches and diaphragm walls is much 
more advanced than that of grouting, so specifications are consi- 
dered standard. One such specification is attached. 



250 



1. SAMPLE SPECIFICATION OF GROUTING JOB 

(Courtesy of Parsons, Brinkerhoff , 
Quade and Douglas, New York, 
New York. ) 



Grout 



Grout shall be non-shrinking, conforming to the requirements 
of Section . 

7th Street Bridge Over Route 1-95 

Description 

The Contractor shall protect the 7th Street Bridge over Route 
1-95 and maintain it safe for public use during the life of the 
Contract, as shown on the contract drawings and as described herein. 

The program shall consist of: 

a) Solidification by chemical grouting of the underlying soil 
situated between the bridge foundations and the proposed tunnels. 

The grouting program shall be capable of producing from 
the groutable soil mass, a solidified soil material having an aver- 
age compressive strength of 100 psi. 

b) Erecting, maintaining and removing a system of adjustable 
temporary supports to permit continuous use of the bridge, should 
settlements develop as a result of the tunnel construction. 

The grouting program must be acceptably completed, and the 
temporary support system must be in place complete and ready for 
operation, before tunnel construction will be permitted to approach 
closer than 200 feet to the nearest abutment of the bridge. 

Approval by the engineer of any equipment, materials or 
methods, shall in no way relieve the Contractor of his responsibi- 
lities for supporting and protecting the structure from damage. 

Pre-Construction Inspection 

In accordance with Section 2, Special Conditions, pre- 
construction inspection of structures will be performed by the 
Authority. The Contractor shall have a representative present 
when the inspection of this structure is being made. 

Limitations of Operations 

The Contractor's attention is directed to traffic restric- 
tions and limitations affecting his operations, as established by 

251 



the District of Columbia Department of Highways and Traffic and 
which are shown on the contract drawings. 

Grouting P rogram 

It is the intent of this program to produce the greatest pos- 
sible uniformity and cohesion of the soil within the designated 
areas shown on the contract drawings. 

The locations and spacing of grout holes and grouting sequence, 
as shown on the contract drawings, are suggested patterns. The Con- 
tractor may revise this pattern. He shall submit full details of 
his proposed grouting program for attaining the required results, to 
the Engineer for approval. Grouting pressure shall not exceed 25 psi 

Details shall include descriptions of: 

a) Geometric layout of grouting pattern 

b) Equipment 

c) Materials 

d) Mixing - capability for closely controlling the 
mix ratio during grouting 

e) Pumping - capability for closely controlling the 
pumping rate during grouting 

f) Gel time - maximum gel time shall be two (2) hours 

g) Proposed grouting pressures 

Should the above mentioned criteria and the uniformity and 
strength requirements not be met, the Contractor shall modify his 
program accordingly. 

Materials 

Grout base material, reactant and catalyst, and their concen- 
trations, shall be selected to bring about the greatest strength 
possible to the grouted soil material, compatible with the exist- 
ing soil conditions. An average compressive strength of the 
grouted soil of 100 psi is required. Reduction of the soil per- 
meability is a secondary consideration. Because of the strength 
requirements, certain types of chemical grout based on acryl amide, 
will not be acceptable. The Engineer reserves the right to reject 
the use of low base material concentrations. Grout shall be adapted 
to a "one-shot" process. 

Grout-in-place shall be chemically stable within the time frame 
of tunnel construction. 

252 



Water used for grout shall be clean and contain no chemicals 
deleterious in any way to the gelling and strength development of 
the grout. The Contractor shall certify to this in writing. 

Dye tracers shall be added to the grout solution. The Con- 
tractor shall certify that the proposed dye will not adversely 
influence the gelling and strength development of the grout. 

Grout materials shall be stored and handled in accordance 
with the recommendations of the manufacturer. 

Grouting 

The grouting program shall be under the continuous, direct 
supervision of personnel who shall have had previous experience 
and be qualified in the application of chemical grout for soil 
strengthening purposes. 

The geometric layout of the holes, shown on the contract 
drawings, are intended to indicate the desired extent of the so- 
lidified soil mass. It is not intended to illustrate an accept- 
able grout pattern. The Contractor shall develop the layout of 
the grout holes, the order in which the holes are to be placed 
and grouted, and the vertical dimension and sequence of grouting 
the lifts for each hole. The maximum spacing of holes logitudi- 
nally along the abutments or pier 3 shall be 4'-0". 

Grout holes shall not be drilled through the bridge footings. 

Should the Contractor plan to use cased grout holes, he 
shall not install the casings by jetting methods. 

Record Keeping 

The Contractor shall maintain complete records of his grout- 
ing operations. Such records shall contain the following mimimum 
information: 

a) Hole number as identified on the Contractor's 
approved plan 

b) Time and date of initiation and completion of 
grouting for each hole 

c) Slope of battered grout holes 

d) Deepest penetration of grout pipe 

e) Grout mix ratio 

f) Concentrations of base material and reactant 

253 



g) Pumping pressure at various depths of grouting 

h) Rate of grout take 

i) Gel time as measured on sample from sample cock 
between mixing chamber and grout pipe 

Items "e" through "i" shall be recorded every time the chemi- 
cal content of the grout and the pumping pressure are changed. 

Temporary Support System 

The Contractor shall be responsible for maintaining the bridge 
structure in a safe condition at all times, including the repair of 
any and all damage to the structure, including bridge approach slabs. 

The Contractor shall install, maintain and operate a system for 
temporarily supporting the bridge superstructure to permit its con- 
tinued safe use by the public. The system shall provide for vertical 
adjustment by jacking methods, at each area of support for each 
stringer. Upon completion of the Contract, the system shall be re- 
moved. 

The support system is shown on the Contract Drawings. The Con- 
tractor shall submit for approval by the Engineer and the D.C. De- 
partment of Highways and Traffic, complete details of the temporary 
support system, including the jacking system and its operation. De- 
tails shall include the reinforcement of stringers to resist jacking 
loads and temporary support reactions. Approval by the D. C. Depart- 
ment of Highways and Traffic and the Engineer, shall not relieve the 
Contractor of his full responsibility under the Contract. The D. C. 
Department of Highways and Traffic, the Engineer, and the Authority, 
have no responsibility. 

Tie rods joining the bridge approach slabs to the bridge abut- 
ments, shall be installed as shown on the Contract Drawings. 



254 



2. STANDARD SPECIFICATIONS FOR ICOS WALLS 

(Courtesy of ICOS Corporation 
of America, New York, New 
York) 

Method of Construction 

The Contractor shall construct the solid reinforced concrete 
wall where shown on the Contract Drawings by the bentonite slurry 
trench process to the end result that the perimeter wall shall be 
watertight (except only that moisture will be permitted to ooze out 
slowly in small drops through fine pores or to emerge like stains of 
sweat) and free from voids or segregation of materials. Where the 
term "watertight" is used in the Specifications, it shall be defined 
as in the preceeding sentence. 

Location, Depth and Width 

The ICOS wall shall begin near the existing ground surface at 
the elevation and location as shown on the Contract Drawings and shall 
extend down through the underlying materials to the depth required by 
the Contract Drawings or as directed by the Engineer. The minimum 
thickness of the ICOS wall shall be f eet. At any given point 
on the wall the inside surface of the wall as construction shall not 
vary in a direction normal to the plane of the wall by more than six 
inches, in addition to the tolerance specified below for vertical 
alignment, from the theoretical surface, based on the dimensions 
shown on the Contract Drawing. Where the inside surface of the wall 
has variations greater than that specified above, the wall variations 
shall be finished to conform to the tolerance above specified by 
chipping, grinding or by applying cement grout. 

Vertical Alignment 

The wall shall be placed straight and the maximum variations 
of the plane of the wall, at any one point on it's inside face, 
from the vertical shown on the Contract Drawing shall be 1% of it's 
height. 

General Requirements for Excavation 

Excavation for the ICOS wall shall be performed to the depths 
and widths required by the Specification and Contract Drawings. Ex- 
cavation with respect to payment, shall include the removal of all 
natural materials encountered in excavating and consistant with the 
information provided by soil borings and other contract documents. 
Any many made obstruction and or any sub-soil condition varying con- 
siderably from what could ordinarily be expected, will be removed on 
a Time and Material basis, or by applying different unit prices. Ex- 
cavation shall include a careful clearing of the bottom of the trench, 

255 



done by appropriate methods, prior to the placing of the concrete. If 
material is excavated below the bottom line of the wall, the Contractor 
shall fill the excess volume with concrete of the same class as that 
for which the excavation was made at his own expense. The excavation 
shall be kept open for construction of the ICOS wall by using bentonite 
slurry. The Contractor shall maintain the stability of the excavated 
trench at all times for it's full depth. The Contractor shall control 
and supervise the use of the bentonite slurry continuously to maintain 
the excavated trench. Under no circumstances the level of the bento- 
nite slurry shall be allowed to drop more than three feet below the 
level of the working platform. An adequate reserve of bentonite slurry 
and pumping equipment shall be provided in order to maintain the exca- 
vated trench at all times. Excavation adjacent to and around existing 
buildings, foundations, structures, and utilities which are to remain 
in place shall be performed without damage to or movement of same or 
the contents thereof and without movement of loss or undermining of 
ground. 

Characteristics of Bentonite Powder 



Composition: 



The bentonite shall be the high swelling Wyoming 
type sodium base bentonite consisting mainly of 
the clay mineral montmorillonite. 



Purity: 



Montmorillonite content: 
Native sediments: 



H 



minimum 
maximum 



Chemical Sodium montmorillonite: 
Composition: Calcium and magnesium 

montmorillonite 



60% minimum 
o maximum 



Viscosity: 



A fully hydrated slurry containing 6% bentonite 
solids (as received basis) when mixed with 94% 
distilled or deionized water shall achieve a 
viscosity of 15.0 centi poises minimum as mea- 
sured by a Fann Viscometer or Stormer Viscosi- 
meter. 



Gelation: 



A fully hydrated slurry containing 6% bentonite 
solids, as prepared for viscosity determination, 
shall have a gelation value of 5 pounds per 100 
square feet minimum as measured by a Fann or 
Stormer instrument. 



Fluid Loss 



A fully hydrated slurry containing 6% bentonite 
solids, as prepared for viscosity determination, 
shall lose no more than 16.5 ccs of fluid when 
subjected to a pressure of 100 psi for 30 
minutes in a cell fitted with a 9.0 cm. Whatman 
No. 50 filter paper. 



256 



Sizing: Pulverized bentonite shall be ground to a fine- 
ness such that 80% minimum passes a USS 200 
mesh screen in dry form. 

Characteristics of Bentonite Slurry 

Composition: The bentonite slurry shall consist of a uni- 
form mixture of high swelling sodium base 
bentonite in water. 

Density: The bentonite slurry shall weigh a minimum of 
64.0 pounds per cubic foot, at a solids con- 
tent of 6%. 

Consistency: The bentonite slurry, at the point of mixing 
and before discharge to the reserve tank shall 
have a consistency of 15 centi poises minimum 
as measured by a Fann Viscometer or Stormer 
Viscosi meter. 

Gelation: The bentonite slurry at the point of mixing 
and before discharge to the reserve tank 
shall have a gelation value of minimum 5 
pounds per 100 square feet as measured by a 
Fann or Stormer instrument. 

Marsh Funnel : Bentonite slurry achieving a flow rate of 60 
minimum through a Marsh Funnel - one quart 
in, one quart out - is acceptable. 

Fluid Loss: Bentonite slurry at the point of discharge 
to the reserve tank shall lose no more than 
16.5 ml of fluid when subjected to filtra- 
tion pressure of 100 psi for 30 minutes 
through a 9.0 cm Whatman No. 50 filter paper. 

PH: The PH of bentonite slurry shall be at least 

8. 

Mixing and Circulating the Bentonite Slurry 

All slurry for use in the trench shall be mixed in a batch or 
continuous mixer adjacent to the trench. No slurry is to be made in 
the trench. Mixing of water and bentonite shall be done by cyclone 
pumps or by other approved methods and shall continue until bentonite 
particles are fully hydrated and the resulting slurry appears homo- 
geneous. The Contractor can vary the characteristics lower than that 
specified above. The Contractor will be allowed to recirculate and 
reuse bentonite slurry, if he so chooses, but he shall be responsible 
at all times for the quality of the slurry and shall avoid at all 
times contamination of the same. Bentonite slurry shall not carry more 
than 10% of solids in suspension when recirculated. 

257 



Joints in I COS Wall 

The wall will be constructed in continuous sections whose 
length shall not exceed 30 feet which will be from now on referred 
to as "panels". The joining of wall panels shall be accomplished 
by use of pipes of suitable diameter at the panel ends, to be ex- 
tracted subsequent to the setting of the concrete, or by other ap- 
proved means. The joints between panels shall be watertight. 

Concrete for I COS Walls 

Concrete for ICOS walls shall be designed for a strength of 
PSI with a slump of eight inches minimum. Maximum size of 



the aggregates should not exceed 3/4 of an inch. Additives of any 
nature should not be used except with written approval of the 
Engineer. 

Placing of Concrete 

Concrete shall be placed in the slurry filled trench by the 
tremie method in such a manner that the concrete displaces the 
slurry and mixing of concrete and slurry does not occur. The con- 
crete shall be placed by a metal hopper and a sectional tremie 
pipe with watertight connections of sufficiently large diameter as 
to permit a free flow of concrete. At the commencement of the pour- 
ing the tremie pipe shall be lowered to touch the bottom of the ex- 
cavation and then raised approximately six inches. The discharge 
end of the tremie pipe shall be kept continuously submerged in the 
concrete for the duration of the pour, which should continue with- 
out interruptions until the concrete has been brought to the 
required elevation. 

Reinforcement 

Reinforcement shall accurately conform in size and position 
to the requirements of the Contract Drawing and of the approved 
Shop Drawings. Bars shall be placed in a reinforced cage and 
wired or secured together in such a way as to provide a cage of 
sufficient rigidity to resist distortion. The reinforcing cage 
shall be lifted by approved methods and shall be suspended in 
the trench during placement of concrete in a manner to prevent 
distortion of the reinforcement and to avoid contact between the 
rods and the soil at the bottom of the trench. Appropriate spac- 
ing devices shall be used to keep the reinforcement away from the 
surface of the trench and to guarantee a minimum cover of two 
inches of concrete. 



258 



F. PATENTS PERTAINING TO GROUTING SOILS 
FOR WATER SHUTOFF OR CONSOLIDATION 

Key: E = Equipment 
M = Material 
P = Process 

Patent No. . Description 

829,664 Process of Solidifying Earthly Ground - N. Mehner - 

(August 28, 1906) - Injection of a mineral substance in 
liquid condition, melted gypsum alone or with other 
material (chloride of magnesium) only example given. (P) 

1,421,706 Process of Excluding Water from Oil and Gas Wells - Ronald 
Van Auken Mills (July 4, 1922) - This patent covers the 
process of introducing into wells, porous sands, or other 
porous rocks or rock-forming materials, one or more soluble 
chemical reagents, either as solids, liquids, gases or muds, 
dry or in aqueous or other solutions, free or in containers; 
and under necessary pressure that is practical, so that the 
said reagent or reagents come in contact with and react 
chemically with each other, react with the rock wall mate- 
rials of the well, or with the dissolved constituents of 
natural waters or other solutions in the wells and inter- 
stices of porous rock in such manner as to cause chemical 
and physical precipitation in the wells and rock interstices 

Mills lists seven examples of his reaction as follows: 
(1) sodium silicate with calcium chloride, (2) sodium 
silicate with magnesium chloride, (3) sodium silicate with 
hydrochloric acid, (4) sodium carbonate or sodium bicar- 
bonate with calcium chloride, (5) sodium sulphate with 
barium chloride, (6) calcium sulfate with sodium silicate, 
(7) calcium oxide, with sodium silicate. (P,M) 

1,815,876 Process of Chemically Solidifying Earth - Michael Muller - 
(July 21, 1931) - Muller's process consists of first 
saturating the earth with silicic acid-containing substances 
and then applying chlorine gas. The result is silicic acid, 
which combines with the quartz-containing constituents of 
the earth. (M) 

1 ,820,722 Process of Solidifying Layers of Ground and Similar Masses - 
Carl Zemlin - (August 25, 1931 ) - This patent covers the use 
of a single uniform chemical solution which reacts with the 
soil to bring about the solidification. The only example 
which Zemlin gives and the only claim which he has covers 
the use of injecting hydrofluoric acid to react with the 
silica in the soil. This reaction gives silica fluoride, 



259 



Patent No . Description 

1,820,722 which in turn continues to act on the earth salts and acids 
Cont'd. to set silica free again and tends to cement together the 
solid particles of soil. (M) 

1,827,238 Process of Solidifying Permeable Rock, Loosely Spread 

Masses or Building Structures - Hugo Joosten (October 13, 
1931 - This patent covers the injection of silicic acid- 
containing materials, followed by the injection of a gas 
which reacts with said materials to form silicic acid, which 
gels in situ from the nascent state and thus integrates the 
treated mass. The only gas suggested is carbon dioxide. 
Joosten also claims the injection of gel -forming chemicals 
followed by a gas. (M) 

2,075,244 Process for Solidifying Earth - Jan Van Hulst (March 30, 1937) 
This patent has three features - in any application any one 
of any combination of these features may be used. The first 
feature is to place in the ground a quantity of coarse 
material such as gravel, gravel stone, stone chippings, or 
rock aggregate around the place where the injection fluid is 
to be introduced. This is supposed to aid penetration. 

The second feature covers a process consisting of introducing 
an aqueous dispersion of a bituminous substance such as 
asphalt and causing this dispersion to coagulate at a desired 
place by suitably controlling the stability of the dispersion. 
The stability is controlled by adding to the dispersion 
coagulation-promoting agents such as electrolytes. 

The third feature of this patent considers using a mixture 
of an aqueous bitumen dispersion with a finely divided 
colloidal substance such as various types of clays (bentonite, 
refractory, potter's fullers earth), water glass, silicic 
acid gel, diatomaceous earth, Cassel earth and other sub- 
stances containing humic acids, gelatine, glue, etc. (M,P) 

2,081.541 Process for Solidifying Soils - Hugo Joosten (May 25, 1937) 
Joosten uses the injection of a single concentrated solution 
containing the silicic acid sol in an unstable or labile 
state. For this purpose the composition specifically des- 
cribed is that which is formed from a concentrated solution 
of an alkali silicate by first adding a suitable precipi- 
tating metal salt solution, particularly such as that of 
soluble zinc salts (for example zinc chloride or sulphate), 
and then bringing the precipitate thus obtained again to 
solution by adding ammonia or substances containing ammonia, 
or by previously admixing such ammonia and thereby preventing 
the formation of the precipitate. The Joosten Process 
consists of first injecting this unstable gel simultaneously 

260 



Patent No . Description 

2,081,541 with the introduction of the material which reacts with the 
ammonia or expel! s it, or followed by the introduction of 
a material which releases the ammonia. He suggests a 
number of chemicals for expelling the ammonia, such as 
hydrochloric acid, acid salts such as sodium bicarbonate or 
bi sulphate, copper salts, iron salts, etc. The main gas he 
suggests is carbonic acid gas. A mixture of air and carbon 
dioxide is carbonia acid gas. Joosten also covers the 
subsequent introduction of a highly concentrated solution 
of calcium chloride. (P) 

2,131,338 Consolidation of Porous als - James G. Vail - 

(September 27, 1938) This patent covers a process consist- 
ing of impregnation with an unstable silicious colloidal 
liquid having an alkaline reaction in the state in incipient 
gel formation, and the said liquid is allowed to set in situ. 
Control of the time of setting can be accomplished by 
dilution or control of pH, for example. The best mixture 
reported consists of a solution of sodium silicate contain- 
ing not substantially less than two mols of silica to one 
mol of sodium oxide with a solution of sodium aluminate, 
the concentration of said solutions being adjusted to 
produce, upon admixture, an unstable dilute liquor setting 
to a full volume alkaline gel within a period of the order 
of thirty minutes. (M) 

2,146,480 Process of Shutting off Water or Other Extraneous Fluid 
in Oil Wells - H. T. Kennedy - (February 7, 1939) - In- 
jection of a material which is hydrolyzed upon contact with 
water to form an insoluble solid matter. Examples: metal 
salt, salt of antimony, arsenic, bismuth, tin and iron, 
antimony trichloride. (M) 

2.152.307 John J. Grebe (to Dow Chemical Corporation) [March 28, 1939] 
An alkali phosphate and a water-soluble soap, the latter in 
excess, are introduced to plug the pores of water strata in 
a well. The treating solution may be forced into the pores 
by a hydrostatic head of oil. (M) 

2.152.308 John J. Grebe (March 28, 1939) - A water-soluble aluminate 
and a water-soluble soap, the latter in excess, are intro- 
duced into wells to plug the pores of water strata. [To Dow 
Chemical Corporation] 

2,156,220 T. H. Dunn (to Stanolind Oil and Gas Co.) [April 25, 1939] 
A solution of magnesium salt, and after it a solution of 
an alkaline hydroxide, are forced into water-bearing strata 
of a well, and excess pressure is held on the system 
sufficiently long for the chemicals to react and plug the 
pores with voluminous precipitate of magnesium hydroxide. (M) 

26 J 



Patent No . Description 

2,169,458 F. A. Bent, A. G. Loomis, and H. C. Lawton (to Shell Dev. Co.) 
[August 15, 1939] - Metal alcohol ates are introduced into 
wells to form water-insoluble hydroxide precipitates for 
sealing off gas and water formations. Slowly hydrolyzing 
alcholates are preferred, e.g., aluminum secondary emyl 
alcoholate and the aluminum alcoholate of ethylene glycol. (M) 

2,176,266 Process for Solidifying Permeable Masses - T. G. Malmberg 
(October 17, 1939) - A water soluble alkali silicate grout- 
ing fluid is described which contains a water soluble acid 
salt of a weak acid to provide a controllable gel time. 
Specific salts claimed are sodium bicarbonate, sodium 
tetraborate and sodium bisulfite. Specific mixture claimed 
is composed of 100 parts by volume of a sodium bicarbonate 
solution containing 66 grams of bicarbonate per liter and 
125 parts by volume of sodium silicate of specific gravity 
1.21. (M) 

2,197,843 Process of Impermeabilizing, Tightening, or Consolidating 
Grounds and Other Earthy and Stony Masses and Structures 
G. H. Van Leeuwen - (April 23, 1940) - This process consi sts 
of injecting a substance which is capable of swelling through 
a solvating agent, the particles of which substance are 
coated with a substance repelling the solvating agent, the 
swelling of said particles being effected in the mass under 
treatment by attracting or adsorbing or combining with or 
wetting by the said solvating agent. 

Where the solvating agent consists of water or an aqueous 
solution of dispersion, the swelling substance may comprise 
such things as colloidal clays, hydroxides of polyvalent 
metals, silicic acid, aluminates or other salts capable of 
swelling with water or of forming liquid crystals, and such 
organic colloids as polyaccharides such as cellulose or 
starch, gum arabic, agar-agar, lipoides, proteins such as 
casein and albumen, organic dyestuffs and the like. Where- 
ever the solvate consists of organic liquids such as oil, 
hydrocarbons, clorinated hydrocarbons, alcohols, carbon 
disulfide, and the like, the swelling substance may comprise, 
for example, rubber, balata, shellac, drying oil polymeri- 
zation products, factis, nitrocellulose, acetyl cellulose, 
soaps and the like which are termed oleophile colloids. 

The substances repelling the solvating agent, such as water, 
which are used in combination with the hydrophile colloids, 
are particularly oils, such as mineral oils, oil fractions 
and residues, tar oils and the like. Such repellent sub- 
stances are called hydrophobic. In the case of the solvating 
agents consisting of organic liquids, such as oils, which are 
used in conjunction with the oleophile colloids, the 

262 



Patent No . Description 

2,197,843 substance repelling the solvating agent may be an oleophobic 
(cont'd.) substance, fn most cases water or an aqueous liquid. Van 
Leeuwen gives a number of examples of injection fluids. 

2,227,653 Process of Stanching and Consolidating Porous Masses - 
Charles Langer - (January 7, 1941) - This patent covers 
the injection of a single solution consisting of water 
glass and a reactive agent comprising an acid and a strong 
coagulant. The existing pH of the sodium silicate is de- 
creased by the addition of an acid in order to obtain a 
weaker alkaline solution. By further adding a suitable 
salt of a heavy metal (iron, copper, lead, zinc and the 
like) as an electrolyte, the latter solution is destroyed 
and coagulates to a gel. By decreasing the pH value the 
sodium silicate solution becomes more sensitive and the 
coagulation to a gel in the ground or other mass being 
treated may be produced at any time desired by means of a 
correspondingly accurate quantity of electrolyte. The 
particular chemicals which appear to be the best, since 
the author specified these, are sodium silicate, hydro- 
chloric acid and copper sulphate. (M) 

2,236,147 W. B. Lerch, C. H. Mathis, and E. J. Gatchell (to Phillips 
Petroleum Co.) - [March 25, 1941] - Formations in wells 
are plugged by introducing a liquid gel-forming material 
comprising a mixture of one part sodium silicate diluted 
with one part of a water solution containing 3-1/2 parts 
hydrochloric acid and 19 parts of sodium bi sulfate 
solution. The acid and bisulfate delay the premature 
setting of the gel until the solution has penetrated the 
formation where it reacts with salts and acids to form 
gel which later solidifies. (M) 

2,238,930 L. C. Chamberlain and H. A. Robinson (to Dow Chemical Co.) 
[April 22, 1941] - The invention relates to methods of 
reducing the permeability of earth or rock formations 
with the formation of a plugging deposit within certain 
strata penetrated by the bore, thus preventing infiltration 
of water by introducing into the formation a water-mi scible 
solution of a stabilizing agent (salts of organic acids) 
and then a nonaqueous water-miscible solution of a metal 
salt capable of forming a precipitate of a basic compound 
by reaction with an aqueous alkaline material. The stabiliz- 
ing agent whereby the precipitation of the basic compounds 
is delayed in the water-bearing stratum and substantially 
prevented in the other gas-bearing stratum. (M,P) 

2,252,271 C. H. Mathis (to Phillips Petroleum Co.) - [August 12, 1941] 
A method of sealing cracks or porous formations by injection 

263 



Patent No . Description 

2,252,271 of a resin-forming liquid is claimed, which is particularly 
Cont'd suitable for plugging limestone and dolomitic materials due 
to its nonacid character. This particular resin is formed 
from an ester of a dicarboxylic acid and a polyhydric 
alcohol, condensed or copolymerized with or without a vinyl 
derivative, using benzoyl peroxide as a catalyst. The 
amount of catalyst added controls the time of setting of the 
fluid to a solid resin after it is placed in the porous 
formation. Being a nonacid, carbon dioxide which might 
otherwise be evolved in a reaction with the limestone, 
cannot impair the effectiveness of plug formation. (M) 

2,258,829 Method of Ground Fixation with Bitumens - J. Van Den Berge 
and F. Dijkstra (to Shell Development Co.) - Hand blown 
asphaltic bitumens are dissolved in an aliphatic solvent, 
e.g., kerosene, naptha, and injected into the formation 
where it is allowed to gel. Solvent should contain less 
than 20% aromatic hydrocarbons. (M) 

2,265,962 F. A. Bent and A. G. Loomis (to Shell Development Co.) - 

[December 9, 1941] - A process for selectively plugging water 
formations in an oil well is claimed. The plugging agent is 
an ester of silicon which hydrolyzes upon contact with water 
in the formation to deposit silica and complex silicon com- 
pounds. The rate of hydrolysis is controllable by changing 
the pH of the treating solution, and/or by selection of 
the particular ester, or its concentration. One of the 
many possible compounds of this class is ethyl -ortho- 
silicate. (M,P) 

2,270,006 H. T. Kennedy (to Gulf Research and Development Co.) - 

[January 13, 1942] - In a method of sealing porous water- 
bearing strata by injecting a compound which forms a plug 
upon contact with water, the plugging agent used is one 
which takes considerable time to set, and the initiation 
of setting is variably controlled by addition of an accel- 
erator. The sealing agents suggested are compounds of 
polyvalent metals carrying at least one OR group, where R 
stands for an alkyl or aryl radical. Examples are zinc 
ethylate ZN (OCa'HOa* aluminum triphenolate A1(0C 6 FL) 3 , and 
tri-chlorstannic ethylate SnCl 3 0C 2 H i ,. Accelerators may be 
silicon tetra chloride, or metal chlorides which form acid 
upon going into solution, such as FeCl 3 , CuCl 2 . (M) 

2,281,810 Earth Consolidation - J. B. Stone and A. J. Teplitz - 

LMay 5, 1942 J - This patent covers a method wherein pervious 
earth formations are injected with an acid organic-silicate 
sol in a state of incipient gellation and adapted to set 
to a gel after an interval of time. The gel time of the 

264 



Patent No . Description 

2,281,810 sol is controlled by the adjustment of the acidity by in- 
Cont'd corporation in the sol of a polybasic acid. Enough poly- 
basic acid is used to delay the setting of the soil in the 
presence of calcium carbonate to between 1/4 of an hour 
and 2 hours. The sol claimed is one comprised of methyl 
silicate mixed with water. The polybasic acids mentioned 
are acids of phosphorus, oxalic acid, and citric acid. (M) 

2,294,294 Treatment of Wells (to Dow Chemical Co.) - [August 25, 1942] 
This patent covers the injection of a material which by 
polymerization, addition or condensation, forms in situ 
a synthetic resin. (M) 

2,307,843 C. H. Mathis and Carl Rampaced (to Phillips Petroleum Co.) 

[January 12, 1943] - Plugging of formations in wells is per- 
formed using a resin-forming liquid prepared by mixing water, 
thiourea, and furfural, allowing the mixture to undergo 
partial condensation in the presence of hydrochloric acid 
added as a catalyst, then adding an alkali sufficient to 
reduce the pH to between 5.5 and 6.5, and finally placing 
the mixture in the formation where further condensation to 
a solid resin will occur. Setting time may be controlled 
by the amount of HC1 used. Resins prepared in this way are 
particularly suited for use in limestone when otherwise a 
reaction with excess acid would occur, producing gaseous 
products which would impair the strength and sealing 
qualities of the set resin. (M) 

2,321,761 C. H. Mathis and Carl Rampaced (to Phillips Petroleum Co.) 

[June 15, 1943] - A synthetic resin suitable for use in wells 
and particularly in limestone strata (where strong acids 
cannot be used) comprises a mixture of furfural, a urethane, 
and a hydrochloric acid catalyst to control the time of 
setting. As the mixture has a pH of about 7, limestone 
formations will not be attacked by it. (M) 

2.323.928 Abraham B. Miller (toHercules Powder Co.) - [July 13, 1943] 
Substantially petroleum-hydrocarbon insoluble pine wood resin 
is used as a soil stabilization agent, alone or in conjunction 
with other stabilizers such as CaCl 2 . The amount used may be 
between 0.12 and 10 percent and preferably is between 0.25 
and 2.5 percent. (M) 

2.323.929 Abraham B. Miller (to Hercules Powder Co.) - [July 13, 1943] 
A method of stabilizing soils by incorporating 0.2 to 10 
percent of a substantially hydrocarbon insoluble pine wood 
resin as an aqueous suspension formed by mixing the resin 
with dilute alkali and saponifying a minor porportion of the 
resin. (M) 

265 



Patent No . Description 

2,330,145 H. A. Reimers (to Dow Chemical Co.) - [September 21, 1943] 
A sealing composition for well formations is claimed com- 
prising 8 to 16 percent by weight of sodium silicate and 
4.7 to 20.5 percent sulfuric acid. By varying the ratios 
of these components in a water solution a great deal of 
control is possible in the time required for setting to a 
firm gel. An extensive table is given showing, for 
different temperatures and compositions of the mixture, the 
minutes duration of a pumpable state and the final set 
strength in grams. By reference to this table it should 
be possible to choose the composition best suited to a given 
well condition (M). 

2,332,822 Milton Williams (to Standard Oil Development Co.) 

[October 26, 1943] - Plugging agents for shutting off 
water strata in oil wells, which are readily removable by 
acidizing, are disclosed and claimed. The preferred agents 
are mixtures of arsenates or phosphates with salts of 
aluminum, calcium, cobalt, chromium, copper, iron, magnesium, 
manganese, or zinc. These precipitate as gels, which are 
readily soluble. A chart is given of setting time vs. 
temperatures for various mixtures of chromium acetate and 
di sodium arsenate, and for mixtures of chromium acetate 
and di sodium phosphate. The feature of acid removability 
should reduce the hazards usually associated with the use 
of gel forming materials in that if oil production is 
accidentally shut off it can be restored. (M) 

2,345,611 W. B. Lerch, C. H. Mathis, and E. J. Gatchell (to Phillips 
Petroleum Co.) - [April 4, 1944] - Claims are asserted to 
the use of aldehyde-urea synthetic resins for plugging off 
water formations in wells. A preferred composition comprises 
thiourea and furfural with concentrated HC1 as a catalyst in 
sufficient quantity to delay the time of set of the mixture 
until it is in place in the formation to be plugged. (M) 

2,349,181 W. B. Lerch, C. H. Mathis, and E. J. Gatchell (to Phillips 
Petroleum Co.) - [May 16, 1944] - A liquid resin-forming 
mixture of furfural and thiourea is claimed as a substitute 
for cement slurry in cementing casing. The setting time 
is controlled by varying the amount of hydrochloric acid 
used as a setting catalyst, and a filler may be added to 
provide bulk without greatly adding to the material cost. 
Bentonite, wood fiber, fine sand, carbon black and other 
similar nonreactive materials are disclosed as fillers. 
A relatively inexpensive resin disclosed but not claimed 
comprises furfural, caustic oil (a waste product from 
caustic washing of cracked distillate) catalyst, and 
filler. (M) 

266 



Patent No . Description 

2,403,643 Method of and Apparatus for Introducing Grout into Subsoil 
G. L. Dresser (July 9, 1946) - A grout pipe, consisting of 
two concentric pipes, which allows the grout pipe to be 
jetted into the soil by washing the soil to the surface 
through the annul us. The grouting slurry is pumped after 
the appearance of the returning wash water indicates that 
clays, fines, etc., have been washed out of the hole. 
Grout pipe is maintained in place, forming a piling after 
the grout has set. (E) 

2,439,833 Cary R. Wagner (to Phillips Petroleum Co.) - [April 20, 1948] 
A formation may be plugged off to water flow by injecting an 
aqueous solution of sodium carboxymetyl cellulose and a 
sufficient amount of a salt to produce a water insoluble 
precipitate. The precipitate may be removed by treating 
with one of the strong bases. (M) 

2,485,527 P. H. Cardwell (to Dow Chemical Co.) - [October 18, 1949] 
Permeable formations penetrated by a well bore are plugged 
by injecting a mixture of two partial condensation products. 
One is the partial reaction product of an aldehyde with an 
alkylated phenol. The other is the partial reaction product 
of an aldehyde, a phenol, and a polyphydroxy benzene selec- 
ted from the group consisting of phloroglucinol and 
resorcinol. The mixture reacts rapidly at normal well 
temperatures with little shrinkage to form a solid plug 
in the permeable formation. (M) 

2,618,570 Process for Preparing a Grouting Fluid - W. C. Blackburn 
(November 18, 1942) - Fifty volumes of tetraethyl ortho 
silicate, 30 volumes of 95 percent ethyl alcohol, one 
volume of water. Let stand 24 hours (to hydrolyze some 
of the silicate) then mix with aqueous alkaline solution. (M) 

2,651,619 DeMello, Hauser and Lambe (September 8, 1952) - Acrylate 
of polyvalent metal and catalyst system. (M) 

2,670,048 Method of Sealing Porous Formations - Paul L. Menaul 

(February 23, 1954) - Patent covers injection dispersion 
of acrylic resin in hydrocarbon followed by injection 
anionic fluid to coagulate or precipitate resin. (M) 

2,706,688 Asphalt Emulsion - H. J. Sommer, R. L. Griffin (April 19, 
1955) - An asphalt emulsion for grouting soil to stabilize 
it and render it impermeable to water. Emulsion contains a 
discontinuous asphalt phase and a continuous aqueous sodium 
silicate phase which also contains an emulsifying agent. 
The type of emulsifying agent is determined by the acidity 
or basicity of its asphalt. The emulsion remains stable 

267 



Patent No . Description 

2,706,688 at pH = 11.3. Reducing pH causes coagulation of the 
Cont'd. emulsion. The degree of pH reduction results in 
reduction in coagulation time. (M) 

2,801 9 985 Soil Stabilization - R. W. Roth - (August 6, 1957) - 

Grouting solution comprised of AM-955 (95% acryl amide, 5% 
N, N 1 - Methyl enebiscryl amide), a redox catalyst 
(peracids and their salts), and nitrilotrispropionamide, 
dissolved in water (M) 

2,860,489 Grouting or Sealing Apparatus - L. E. Townsend, (November 18, 
1958) -A grouting packer, with packing elements expanded 
against open hole walls by hydraulic pressure, provided by 
piston arrangement. (E) 

2,940,729 Control System for oil Stabilizer Polymerization - David 
H. Rakowitz - (June 14, 1960) - Ferrocyanides and ferri- 
cyanides used as gelatin inhibitor in acryl amide polymer 
(AM-955) grouting fluid. The cyanides provide a means for 
predictably delaying gelation. (M,P) 

2,947,146 Sealing Method for Underground Cavities - R. L. Loofbourow 
(August 2, 1960) - Walls of underground excavations are 
sealed by applying sealant to walls and forcing it into 
the surface by increasing air pressure in the excavation. (P) 

3,012,405 Method and Composition for strengthening Loose Grounds - 

C. Caron (to Societe dite: Solentanche (S.A.R.L.) - Paris) 
[December 12, 1961] ■■ A water soluble alkali metal silicate 
grouting fluid is gelled by the addition of a hydrolyzable 
ester such as ethyl acetate. A surfactant such as iso- 
propyl formate is added to form a stable emulsion of the 
ester and the silicate. Increasing the concentration of 
isopropyl formate speeds the gel time. (M) 

3 , 021 , 298 Soil Stabilization with a Composition Containing an 

Acryl amide, a Bisacryl amide, and Aluminum and Acryl ate lons- 

D. H. Rakowitz (to American Cyanamid Co.) [February 13, 1962] 
A grouting solution comprised of an acryl amide, a bis- 
acryl amide, aluminum or chromium sulfate or nitrate. Cross- 
linking agents such as N, N 1 methylene bisacryl amide are 
also employed. A redox catalyst system is composed of a 
water soluble peroxy compound and a reducing compound to- 
gether with nitrilotrispropionamide. Insolubilization is 
accomplished by cross-linking three covalent bonds and three 
covalent bonds and three ionic bonds. The set material 
stabilizes the soil and renders it impermeable to water. (M) 



268 






Patent No . Description 

3,053,675 Process of and Material for Treating Loose Porous Soil - 
S. J. Rehmar, N. L. Liver (to Intrusion Prepakt, Inc.) 
[September 11, 1962] - A grouting fluid comprised of a 
water-soluble lignin sulfonate, inorganic hexavalent 
chromium salt and an acid salt such as aluminum sulfate. 
The grouting fluid is injected into sandy soil, allowed 
to gel, whereupon the soil is subsequently grouted with 
a slurry such as cement. (M) 

3,091,936 Resinous Composition - L. A. Lundberg, J. C. Schlegel, 

J. E. Carpenter (to American Cyanamid Co.) - [June 4, 1963] 
A polyester resin is described that is employed to bond 
formations together, to prevent rock falls from the roofs 
of mines. The composition is designed to cure rapidly 
at low temperatures, and is comprised of the polyester 
resin, an inhibitor, for example phenol or monoalkyl 
phenols, a promoter consisting of a fatty acid cobalt 
salt together with a tertiary monoamine and a stabilizer 
consisting of a resin-soluble copper salt and a compound 
containing a basic imino group and salts thereof. (M) 

3,108,441 Process for Sealing Soils - C. E. Watson (to California 

Research Corporation) - LOctober 29, 1963]. A wax emulsion, 
containing a surfactant, is used to establish a water- 
impermeable layer in soil. Wax particles are 0.1 to 2.5 
microns in size. Wax concentration is from .05% to 2.0% 
by weight. The choice of surfactant type, i.e., cationic, 
nonionic or anionic, is determined by soil type and seepage 
rate before treatment. (M) 

3,127,705 Water Leakage Inhibiting Masonry Treatment - H. L. Hoover 
[April 7, 1964] - Water soluble polymeric acrylic acid 
material or water soluble metallic salts thereof are in- 
jected into the soil in the vicinity of a subgrade masonry 
wall. The ground water carries the material to the leaking 
masonry wall, where it reacts with insolubilizing alkaline 
earth metal ions present in the masonry structure, forming 
a water-insoluble, impermeable film on the masonry surface. 
(M) 

3,166.132 Grouting Tool - T. P. Lenahan, B. J. Bradley, A. H. Limbaugh- 
(to Halliburton Company) -[January 19, 1965] - A grouting 
tool is described which allows lateral ejection of grouting 
fluid along its entire length after it has been driven to a 
desired depth. The tool is initially driven with the aid 
of a jet of water through a nozzle at the bottom end of 
the tool. A removable tube is retrieved from the tool, 
exposing longitudinal slots in the body of the tool. The 
nozzle is then shut off with a ball dropped into the tube, 

269 



Patent No . Description 

3,166,132 after which the grouting fluid is pumped into the tool and 
through the longitudinal slots. (E) 

3,202,214 Preparation and Use of Sodium Silicate Gels - H. C. 

McLaughlin (to Halliburton Company) - [August 24, 1964] 
Improved gelling agents for silicate grouting fluids are 
described. One type includes agents which undergo the 
Cannizzaro reaction in the presence of sodium silicate 
solution. Included in this group are the aldehydes having 
no hydrogen atom or the alpha carbon, such as formaldehyde, 
glyoxal , benzaldehyde, furfural and trimethylacetaldehyde. 
Another group of gelling agents are those that undergo an 
oxidizing reaction to form organic acids. For example, 
methanol, formaldehyde, glycerin, ethylene glycol, glucose, 
sucrose, furfural and flyoxal. The oxidizing agent used to 
effect the reaction to form the organic acids may be per- 
oxides, persul fates, perbonates and hydrogen peroxide. The 
particular advantage with these gelling agents is that a 
time delay occurs before a sufficient amount of gelling 
agent is formed to cause gellation. This delay allows 
placement of the grouting fluid for a considerable distance 
through the soil . (M) 

3,208,226 Process for Stabilizing Soil - J. J. Flovey (to American 

Cyanamid Co. J [September 28, 1965] - An aqueous solution of 
ureaformaldehyde resins, containing an acidic catalyst, is 
injected into soil, where it is allowed to harden. The 
resultant soil is stabilized and water-impermeable. Acidic 
catalysts that may be used include inorganic acids such as 
hydrochloric, sulfuric, nitric, phosphoric, acetic, 
chloracetic, trichloracetic, or acid salts such as ammonium 
bi sulfate, sodium bi sulfate, ammonium chloride, ammonium 
nitrate, or organic acids such as oxalic, maleic, paratoluene 
sulfonic, or other acidic materials such as aniline hydro- 
chloride and the like. (M) 

3,221,505 Grouting Method - R. J. Goodwin, F. L. Becker (to Gulf 

Research & Development Co.) - [December 7, 1965] - A water- 
permeable soil is rendered impermeable by injecting a 
water miscible non-aqueous fluid, e.g., alcohol, to dis- 
place the water from the area to be grouted to another 
drilled hole. While pressure is maintained on the holes to 
prevent invasion of dewatered area, a gaseous agent, e.g., 
silicon tetra fluoride, is injected into the soil. The gas 
flows to the boundaries of the dewatered zone, where it 
reacts with the groundwater, generating a precipitate which 
plugs the pore spaces in the soil, and prevents the migration 
of fluids. (M,P) 



270 






Patent No . Description 

3,223,163 Composition and Method for Stabilization of Soil - R. R. Koch, 
J. Ramos, H. C. McLaughlin - (to Halliburton Company) - 
[December 14, 1965] - Finely divided fillers, e.g., silica 
flour, gilsonite, asphaltic pyrobitumens, barite, talc, 
bauxite, scoria, are used to allow controlled placement of 
various grouting fluids. Particle size of the fillers range 
from 10 to 180 microns, allowing controlled fluid loss from 
fissures and vugs to the pore spaces in permeable soil masses. 
Grouting fluid types are chrome-lignin, acrylamide and alkali 
metal silicates. (M) 

3,243,962 Method and Apparatus for Treating Soil - G. R. Ratliff, 
(April 5, 1966) - A grouting tool is described, which 
contains a plurality of valved ports along its length. 
By manipulation the ports can be selectively opened or 
closed, controlling the point in the grout hole at which 
grouting fluid is injected into the soil. (E) 

3,280,196 Hydraulic Grouting Packer - B. Q. Barrington (to Halliburton 
Company) - [October 25, 1966] - Packer is equipped with an 
inflatable sleeve, operated by the pressure of the grouting 
fluid being pumped. (E) 

3,293,864 Method and Apparatus for Impregnating Masses of Material - 
H. H. Hagius, W. W. Brown (to Halliburton Company) - 
[December 27, 1966] - A controlled method for injecting 
grouting fluid into earthen material such as water- 
saturated backfill adjacent a foundation wall. The grout 
pipe is inserted and sealed through a flexible barrier 
wall. Excess water is pumped out of the backfill material. 
Compressed air is then injected, forcing the groundwater 
away from the wall, whereupon the grouting fluid is in- 
jected and pressure maintained until the fluid has set. (E,P) 

3,294,563 Silicate Grout - D. R. Williams (to Cementation Co., Ltd, 
London) - [December 27, 1966] - An alkali -metal silicate 
grouting fluid containing a metal complex and a sequester- 
ing agent which results in a slow release of metal ions. 
The metal ions react with the silicate to form water-in- 
soluble gels. Preferred sequestering agents are oxalic and 
citric acids. The metals are those capable of forming 
hydroxylated ions in a pH range of 4 to 11, and include 
barium, magnesium, calcium, strontium, titanium, aluminum, 
thorium, zirconium, chromium, molybdenum, manganese, iron, 
nickel, tin, lead and zinc. (M) 

3,306,756 Composition and Method for Stabilizing Soil - G. A. Miller 
(to Diamond Alkali) - [February 28, 1967] - The gelation 
of an alkali-metal silicate grouting fluid is accelerated 
by the addition of compounds including carboxylic acids, 

271 



Patent No . Description 

3,306,756 esters of carboxylic acids, ketones, alcohols, linear 
Cont'd. aldehydes (other than formaldehyde), cyclic polymers of 
the lower alkyl aldehydes and dioxane. (M) 

3,324,665 Method of Stabilizing Piles - T. J. Robichaux, S. G. Gibbs, 
R. M. Jorda - (June 13, 1967) - [to Shell Oil Co.] - A 
thermo-setting resin is pumped into loose soil through holes 
in a pile, resulting in the soil and pile becoming a unified, 
load-bearing structure. Preferred resins are of the epoxy 
type, which includes epoxidized esters of unsaturated mono- 
hydric alcohols and polycarboxylic acids, epoxidized esters 
of unsaturated alcohols and unsaturated carboxylic acids, 
polyethylenically unsaturated polycarboxylic acids. Curing 
agents include polyamides and polyamines. (M) 

3,332,245 Method for Injecting the Components of a Phenoplastic 
Resin into Slightly Watertight Grounds - C. Caron (to 
Solentanche, Paris) - [July 25, 1967 J - Components of a 
phenolic resin are injected into loose soil, where they 
react to form a hard resin, solidifying the ground and 
rendering it impermeable. The resin components include 
resorcinol, water, formaldehyde and amonium persulfate 
and optionally ammonia and sodium bicarbonate. The 
monomer solution has a viscosity of 3 centi poises. For 
\/ery rapid polymerization, the diluted phenolic is 
pumped separately from the catalyst solutions, which is 
added by a metering pump at the point of injection. 
Without catalyst, the mixture polymerizes only after 
weeks. The pump time is adjusted by the amount of 
catalyst added. The solution remains stable to pH of 
6, but polymerizes when taken to the acid or alkaline 
side. (M) * 

3,334,689 Method of Stabilizing or Sealing Earth Formations - 

H. C. McLaughlin (to Halliburton Company) - [August 8, 1967] 
A grouting solution with low initial viscosity capable 
of forming a stiff tough gel, with controllable gel times. 
Typical formulation includes aery 1 amide, trial lyl phosphate, 
dimethyl aminopropionitrile, di sodium phosphate duohydrate, 
potassium ferri cyanide, ammonium persulfate. Gel times 
are controlled by varying the amount of potassium ferri - 
cyanide. (M) 

3,335,018 Composition and Method for Stabilizing Soil - C. E. Peeler, 
A. D. Bergman, D. J. 01 ix (to Diamond Alkali ) - [August 8, 
1967] - A grouting slurry is described containing an 
alkali -metal silicate, amide, hydraulic cement and a 
reactive salt. Advantages claimed are no shrinkage upon 
curing and no cracking. (M) 

272 



Patent No . Description 

3,374,934 Soil Stabilization and Grouting Method - J. Ramos and 

R. F. Rensvold (to Halliburton Company) - [March 26, 1968] - 
Attapulgite and asbestos are described as more efficient 
suspending agents for inert fillers (such as silica flour) 
in grouting slurries. (M) 

3,391,542 Process for Grouting with a Tri -Component Chemical Grouting 
Composition - F. W. Herrick, R. I. Brandstrom (to Rayonier, 
Inc.) - [July 9, 1968] - A grouting fluid is described, 
composed of a formaldehyde-reactive, water soluble, alkaline 
polyphenolic derivative of coniferous bark or a tannin of 
the catechin or condensed type, formaldehyde and a soluble 
salt of chromium iron or aluminum. Control of the gel 
time is governed by the concentration of the metallic salt, 
and can be regulated from a few seconds to several hours. (M) 

3,416,604 Epoxy Resin Grouting Fluid and Method for Stabilizing 
Earth Formations - Roger F. Rensvold (to Halliburton 
Company) - [December 17, 1968] - A grouting fluid com- 
prised of an epoxy resin and an alkyl amine wherein each 
alkyl group is a tertiary alkyl group containing from 
about 4 to about 8 carbon atoms used in stabilizing and 
sealing earth formations. Solid fillers, e.g., silica 
flour may be added. (M) 

3,417,567 Soil Stabilization - E. Higashimura, M. Ishii, Y. Ishikawa- 
(to Mitsubishi Rayon Co., Tokyo) - [December 24, 1968] - 
An aqueous grouting fluid, a typical representative being 
comprised of calcium acrylate, a reaction product of 
glycerine and methyl acrylate, and hydroxyethyl acrylate. 
Glycidyl acrylate, acrylamide, tetraethylene glycol mono- 
acrylate glycidylacrylate can be used in alternative modifi- 
cations. Gel times are controlled by a catalyst system which 
may contain ammonium persulfate, dimethylaminopropionitrile, 
sodium thiosulfate. The gelled material is water insoluble 
and resistant to syneresis. (M) 

3,421,585 Grouting, Plugging and Consolidation Method - L. H. Eilers, 
C. F. Parks (to Dow Chemical Co.) - [January 14, 1969] - 
An aqueous gel able grouting composition comprised of a water- 
soluble polymer (acrylamide) a hydrogen ion source (hydro- 
chloric acid), a water-soluble sodium silicate, capable of 
changing from a water-thin fluid to a stiff gel. Control 
of gel time is established by acid concentration, while 
control of gel strength is a function of sodium silicate 
content. 

3,490,933 Grouting Composition - L. E. Van Blaricom, H. R. Deweyert, 
N. H. Smith (to ITT Rayonier Corp.) - [January 20, 1970] 
See U.S. Africa Patent 68/1381 

273 






Patent No . Description 

3,604,213 Chemical Grouting Proportioning Pumping Method and Apparatus 
H. L. Parsons - (September 14, 1971) - The hydraulic flow 
from a hydraulic pump is divided to drive two rotary hydrau- 
lic motors, each in turn driving a rotary pump. The outlet 
line of each motor is equipped with a valve to control the 
pump rate. (E) 

3,660,984 Stabilizing Soils - A. R. Anderson (to J. J. Packo) - 

[May 9, 1972] - Unstable and permeable soils are stabilized 
or solidified by injecting a fluid composed of a metal alkyl, 
a metal alkyl hydride or a metal alkyl halide and a liquid 
or solid compound of a tetravalent metal such as silicon, 
titanium, zirconium or hafnium. A preferred mixture is 
20% diethyl zine with 80% tetraethoxysilane. The mixture 
reacts with the moisture in the soil, the rate of reaction 
proportional to the amount of water present. (M) 



3,686,872 



Soil Grouting Process - A. J. Whitworth, S. Y. Tung, 
E. A. Hajto (August 29, 1972) - A grouting fluid consisting 
of an alkaline aqueous, low viscosity, gel-forming solution 
containing a polyphenol ic vegetable tannin extract, an 
aldehyde and a gelling agent. Control of the gelling rate 
is achieved by the type and dispersible in alkaline aqueous 
media, and are compounds of silicon, vanadium, molybdenum, 
manganese, titanium, copper, zinc and zirconium. Typical 
specific materials cited are sodium metasilicate, sodium 
metasilicate nonahydrate, potassium silicates, ammonium 
fluorilicate, vanadium pentoxide, potassium permanganate, 
cupric sulfate, zinc chloride and zirconium nitrate. Sodium 
silicates and vanadium peroxide are preferred. (M) 

3,695,356 Plugging Off Sources of Water in Oil Reservoirs - P. A. 
Argabright, C. T. Presley, H. C. Bixel (to Marathon Oil 
Company) - [October 3, 1972] - Aqueous solutions of iso- 
cyanuric salts are injected into the water-bearing for- 
mations, where they hydrolyze to form plugging precipitates. 
The rate of precipitation is controlled by varying the pH.(M) 

3,696,622 A Method of Soil Stabilization and Leakage Prevention - 
W. Tohma, T. Murata, N. Nahamura, A. Kudo (to Sumitomo 
Durez Co., Ltd., Tokyo) - [October 10. 1972] - Soil 
stabilization and sealing is accomplished with a resin 
composition comprised of a water soluble, strongly alkaline 
liquid phenol -formaldehyde resin. The gelation control agent 
is a lactone containing urea, a urea derivative and a basic 
or neutral salt. (M) 



274 



Patent No . Description 

3,719,050 Soil Stabilization Method - H. Asao, T. Hihara, S. Endo, 

C. Furuya, K. Sano (to Toho Chemical Industry, Ltd., Tokyo)- 
[March 6, 1973] - Soil is stabilized by injecting a poly- 
urethane polymer, which solidifies upon reacting with water. 
The reaction time is shortened by the addition of an acidic 
material. Example of accelerator is m-tolylenediamine. 
Example of a retarder is p-nitrobenzoyl chloride. (M) 

3,802,203 High Pressure Jet-Grouting Method - Y. Ichise, A. Yamakado, 
S. Takano (to Y. Ichise) - [.April 9, 1974] - A grouting 
tool designed to inject water, grouting fluid and compressed 
air into a formation. Three coaxial jets at right angles to 
the axis of the tool are used to inject the compressed air 
and the grouting fluid. The outer coaxial jet is for com- 
pressed air, while the two inner coaxial jets are for a 
two-component grouting fluid. A single component grouting 
fluid may also be used with the tool. The tool is also 
equipped with a water jet in line with the long axis of 
the tool, fitted with a ball check valve. This jet is used 
to drive the tool to the desired depth. By jetting the 
grouting fluid while the tool is slowly raised, a curtain 
wall 7-18 mm thick is formed, about 70 mm long. By rotating 
the tool, a horizontal "panel" or barrier is formed. The 
pressure required for the grouting fluid is 50 to 1000 kg/cm 2 
whereupon the velocity of the fluid through the jets is 
100-450 m/sec. Below a pressure of 50 kg/cm 2 , the cutting 
effect of the jet is not obtained. The air pressure may 
range from 3-7 kg/cm 2 . (E,P) 



275 



FOREIGN PATENTS 

Patent No . Description 

68/1381 Grouting Composition - (Union of South Africa) - L. E. Van 
(See USP Blaricom, H. R. Deweyert, N. H. Smith (to Rayonier, Inc.) - 
3,490,933) [July 12, 1967] - An aqueous gel forming composition compris- 
ing an aqueous solution containing 25-45% sulfonated poly- 
phenolic material extracted from coniferous tree bark and 
quebracho wood, 5-40% water soluble dichromate and 5-25% 
borax, with a pH of 8-10.5. The borax is added as a 
retarder to control the gel time. (M) 

222,316 Method for the Stabilization of Soils - (Australia) - R. W. 
Roth (to American Cyanamid) - [June 23, 1959] - An aqueous 
grouting fluid containing a bisacryl amide, acryl amide and 
the catalyst system comprising varying proportions of 
nitrilotrospropioramide retarder and a pexory catalyst. 

385,751 John J. Grebe and S. M. Stoesser (to Dow Chemical Co.) - 
[December 19, 1939 - Canada] - Porous well formations are 
plugged with a water-insoluble viscid material and a water- 
soluble organic solvent, e.g., hardwood pitch and acetone. 
(M) 

441 ,622 Method of Stabilization of Mountain Layers - Hugo Joosten 
(March 9, 1927 - Germany) - The patent covers a method of 
stabilization of quartz-containing earth based on the 
reaction of silicic acid-containing material and soluble 
salts or acids, with or without filling materials. The 
reaction produces silicic acid in situ, which improves the 
stability of the mass. (M) 

849,712 N. V. DeBataafsche Pet. Mi j . (November 30, 1939 - France) 
Water-bearing formations in a well are plugged up by treat- 
ment with a fluosilicate and an alkali, e.g., with a fluo- 
silicate of Ca, Mg, Pb, Fe, aniline, di phenyl amine, and 
others, and an alkali, such as NH<,0H, NaOH, KOH. A number 
or products precipitate, including some by interaction with 
natural brine components. As equivalents of fluosilicates, 
the fluotitanates and a few analogues are disclosed. (M) 



276 



LIST OF GROUTING SPECIALISTS 



Grouting Specialists in the United States 

Alabama Waterproofing Company, Inc. 
P. 0. Box 692 - Route 18 
Birmingham, Alabama 35210 
Attn: Will Max Harden 



Hayward Baker Company 
1875 Mayfield Road 
Odenton, Maryland 21113 

Attn: Wallace H. Baker, President 



Chemgrout Incorporated 
805 East 31st Street 
LaGrange Park, Illinois 60525 
Attn: Doring Dahl , President 



Chemical Soil Solidification Company, Inc. 

1728 Broadway 

Hewlett, Long Island 11557 

Attn: Martin Riedel, President 



Chemical Soil Solidification Company, Inc 
7650 South Laflin Street 
Chicago, Illinois 



Dean Jones Contractor 
410 Opal Street 
Clinton, Oklahoma 73601 

Attn: Dean Jones, President 



Eastern Gunite Company 
240 Rock Hill Road 
Bala Cynwyd, Pennsylvania 19004 
Attn: P. A. Heaver, President 



Foundation Sciences, Inc. 
Cascade Building 
Portland, Oregon 97200 

Attn: Ken Dodds, President 



277 



Geologic Associates, Inc. 

Reynolds Road 

Franklin, Tennessee 37064 

Attn: Raymond T. Throckmorton, Jr., President 



Geron Restoration Company 
7 Wells Street 
Saratoga, New York 12866 

Attn: Gerald Benoit, President 



Halliburton Services 
P. 0. Drawer 1431 
Duncan, Oklahoma 73533 

Attn: Tom Lenahan, Grouting Consultant 



Halliburton Services 

Nine Parkway Center - Suite 275 

Pittsburgh, Pennsylvania 15220 

Attn: Lloyd Want! and, Superintendent 



Hunt Process Company, Inc. 
P. 0. Box 2111 

Santa Fe Springs, California 90670 
Attn: Slade Rathbun, Manager 



Intrusion Prepakt Company 
13224 Shaker Square 
Cleveland, Ohio 44120 

Attn: Bruce Lamberton, Vice President 



Northern Systems, Inc. 
20702 Aurora Road 
Cleveland, Ohio 44146 

Attn: Ray Tartabini , President 



Penetryn Systems, Inc. 
424 Old Niskayuna Road 
Latham, New York 12110 

Attn: Ed Stringham, President 



278 



Pressure Grout Company 
1680 Bryant Street 
Daly City, California 94015 
Attn: Ed Graf, President 



Raymond International, Inc. 
Soil tech Department 
6825 Westfield Avenue 
Pennsauken, New Jersey 08110 
Attn: Joe Welsh, Manager 



SOLINC 

Soletanche and Rodio, Inc. 
6849 Old Dominion Drive 
McLean, Virginia 22101 

Attn: Gilbert R. Tallard, General Manager 

Terra-Chem, Inc. 

P. 0. Box 46 

George's Road 

Dayton, New Jersey 08810 

Attn: Herbert L. Parsons, President 



Warner Engineering Services 

2905 Allesandro Street 

Los Angeles, California 90039 

Attn: James Warner, President 



279 



Core Drilling - Grouting Specialists 



Boyles Brothers Drilling Company 

P. 0. Box 58 

Salt Lake City, Utah 84110 

Attn: F. E. Sainsbury, Vice President 



Continental Drilling Company 
2810 North Figueroa Street 
Los Angeles, California 90065 

Attn: Richard 0. Theis, President 



Robert P. Jones Drilling Company 
3512 North 36th Street ' 
Boise, Idaho 83703 

Attn: Robert P. Jones, President 



W. J. Mott Contractor Inc. 
817 - 8th Avenue 
Huntington, West Virginia 25701 
Attn: William H. Mott 
F. C. Stump 



Pennsylvania Drilling Company 
1205 Chartiers Avenue 
Pittsburgh, Pennsylvania 15220 

Attn: Thomas B. Sturges, Vice President 



Freezing 

Terrfreeze Corporation 
8551 Backlick Road 
Lorton, Virginia 22079 

Attn: John Schuster, Manager 



280 



Grouting Specialists in Europe 



Soil Mechanics, Ltd. 

Foundation House 

Eastern Road 

Bracknell, Berkshire, England 



Ing. G. Rodio & c.s.p.A. 

Strada Pandina 

20077 Casalmalocco (Mi) 

Italy 



Soletanche Entreprise 
7, rue de Logelback 
75017 Paris, France 



Bachy 

Paris, France 



Consonda 
Milan, Italy 



I COS 

via Luciano Manara, 1 

20122 Milano, Italy 



Geosonda 

Via Girolamo da Capri, 1 

Roma, Italy 



Nederhorst Grondtechniek 
Postbus 177 
Gouda, Holland 



SWIBO Ges. m.b.H. 

Kramergasse 3/6 

A- 1010 Vienna, Austria 



The Cementation Co., Ltd, 
Cementation House 
Mitcham Road 
Croydon, Surrey, England 



Keller Division 
Guest, Keen & 
Nettlefords, Ltd. 
Frankfort, Germany 



281 



H. CHEMICAL GROUTING MATERIAL SUPPLIERS 



American Cyanamid Company 

Industrial Chemicals & Plastics Division 

Wayne, New Jersey 07470 

Attn: William J. Clarke 



Borden Chemical Company 
Division of Borden Company 
180 East Broad Street 
Columbus, Ohio 43215 

Attn: Charles E. Markhott 



Diamond Shamrock Chemical Company 
Divisional Technical Center 
Paintesville, Ohio 44077 

Attn: W. T. Gooding, Manager 



E. I. DuPont de Nemours 
Wilmington, Delaware 



Philadelphia Quartz Company 
Public Ledger Building 
Independence Square 
Philadelphia, Pennsylvania 19106 



3M Company 
Building 219-1 
3M Center 

St. Paul, Minnesota 55101 
Attn: John F. Evert 



282 



I. GROUTING EQUIPMENT SUPPL I E RS 



Company 



Type of Equipment 



Chem Grout 

La Grange Park, Illinois 



Cement Slurry Equipment 
Chemical Grout Equipment 



Gardner Denver 
Quincy, Illinois 



High-Pressure Portland 
Cement Pumps 



Halliburton Services 
Duncan, Oklahoma 



Low Volume, High Pressure 
Chemical Pumps 
Two-Stream Grout Manifold 
Grout Drive Rods 
Grout Packers 



Kerr Pump Company 
Ada, Oklahoma 



High-Pressure Chemical 
Pumps 



Robins and Meyers 
Springfield, Ohio 



Portland Cement and 
Chemical Low-Pressure 
Pumps 



283 



J. BENTONITE SUPPLIERS 



Company 



Location 



Tradename 



American Colloid 
Barium Supply Company 

Baroid Division 

Chemco, Inc. 

Gulf Coast Pre-Mix 

IMCO Services 

Louisiana Mud 
Magcobar 

MilChem 
Wyo-Ben Products 



Chicago, Illinois 
Houston, Texas 

Houston, Texas 

Harvey, Louisiana 
Lafayette, Louisiana 
Houston, Texas 

Lafayette, Louisiana 
Houston, Texas 

Houston, Texas 
Billings, Montana 



Premium Gel 

Basco Gel 

Basco Double Yield 

Aquagel 
Quick Gel 

Chemco Gel 

Pre-Mix Gel 

IMCO Gel 
IMCO HYB 

Lamco Gel 

Magcogel 
Kwik-Thick 

Mil -Gel 

Hydrogel 



284 



K. CURRENT RESEARCH IN GROUTING TECHNOLOGY 



A summary of the ongoing research in the area of grouting was 
obtained from Smithsonian Science Information Exchange, Inc. 

The following research was reported which was pertinent to 
soils grouting: 

a. "In Situ Improvement of the Properties of 
Soil by Grouting" 

This project is a study of the effect of injections 
as a function of the nature of the soil and the 
equipment used. Both waterproofing and strengthening 
will be studied. 

Sponsored by the French Government with 
work done by regional laboratories in 
France. 



b. "Compaction of Soil During Pressure Grouting" 

This study aims at rationalizing the mechanisms 
controlling the process. 

Work being done by Cementation Co., Ltd. 
in England. 

One project was reported dealing with rock grouting. It deals 
with stopping water seepage in road tunnels by injection of chemi- 
cals into the rock. Work is being done in Oslo, Norway by the State 
Road Laboratory. 

A research contract has been awarded by the Federal Highway Ad- 
ministration, Department of Transportation, for a study to conduct 
a comprehensive survey to find or develop improved chemical grout 
materials, which are lower in cost than present equivalent grouts 
and suitable for waterstop or strength increase in soils. Also in- 
cluded in the study is the development of a standard laboratory test 
for evaluating grouts. 



■it U.S. GOVERNMENT PRINTING OFFICE; i 9 7 6 -2 1 1 - 1 7 3/7 5i 



285 






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